Abrego Garcia is jailed in Tennessee awaiting trial on human trafficking charges.

Mr. Musk, who poured millions of dollars into the Trump campaign last year, spearheaded a massive government restructuring project in recent months, cutting thousands of federal jobs before he returned to running his businesses last week.

Mr. Musk’s vociferous opposition to the president’s bill, expressed on social media, touched off the two men’s dispute on Thursday. But he has since removed his most vicious social media posts about Mr. Trump, notably his accusation that the Trump administration was blocking the release of information about the convicted sex offender Jeffrey Epstein because the files somehow implicated the president, who had been a friend of Mr. Epstein’s for years before falling out with him.

Another of Mr. Musk’s deleted posts was a vow that his company SpaceX would decommission its Dragon spacecraft, which NASA has used to transport crew to the International Space Station. That comment came in response to a post by Mr. Trump on Truth Social that he could save the government billions of dollars by canceling Mr. Musk’s federal contracts.

Mr. Trump was ask on an Air Force One flight to New Jersey on Friday how seriously he was considering canceling Mr. Musk’s contracts. Mr. Trump did not rule it out.

“He’s got a lot of money. He gets a lot of subsidy, so we’ll take a look at that,” Mr. Trump said. “Only if it’s fair for him and for the country, I would certainly think about it. But it has to be fair.”

The sudden move by the Trump administration to bring Mr. Abrego Garcia back to the United States after months of fighting efforts to do so could end the most high-profile legal battle over the president’s authority to rapidly seize and deport undocumented immigrants without a hearing.

Mr. Abrego Garcia’s lawyers said that they welcomed their day in court and that the government’s decision undercut its efforts to keep him in El Salvador.

“It’s now up to our judicial system to see that Mr. Abrego Garcia receives the due process that the Constitution guarantees to all persons,” said Andrew Rossman, a lawyer for Mr. Abrego Garcia.

In March, Mr. Abrego Garcia, a contractor from Maryland, was picked up in a Trump administration dragnet and deported along with several other men to a prison in El Salvador, even though an immigration judge had ruled he should not be sent there because he had reason to fear for his safety.

Now Mr. Abrego Garcia, a native of El Salvador, faces more than just the accusation that he was in the country illegally. A 10-page indictment — filed in the Federal District Court in Nashville in May and unsealed on Friday — accuses him not only of being a member of the violent street gang MS-13 but of being part of a ring that smuggled undocumented Latin American immigrants into the United States.

In court papers seeking his pretrial detention, prosecutors said Mr. Abrego Garcia had played “a significant role” in the conspiracy to smuggle immigrants, including unaccompanied minors. They added that smuggling immigrants was Mr. Abrego Garcia’s “primary source of income” and that he had transported about “50 undocumented aliens” each month for several years.

The indictment relies on five “confidential informants” who told investigators they were also part of the ring. Two of the informants told federal authorities that Mr. Abrego Garcia regularly picked up illegal immigrants in Houston and drove them to other parts of the country, starting in 2016.

Mr. Abrego Garcia is also accused in the indictment of smuggling weapons from Texas to Maryland and of abusing some of the female immigrants, though he is not charged in connection with those acts.

The smuggling charges stem from a traffic stop on Nov. 30, 2022, when Mr. Abrego Garcia was pulled over for speeding by the Tennessee Highway Patrol on Interstate 40 East, in Putnam County, the indictment said.

Officers determined that the Chevrolet Suburban he was driving had been altered with “an aftermarket third row of seats designed to carry additional passengers,” the indictment said. It also noted that there were “nine Hispanic males packed into the S.U.V.” and that none of them “had luggage or even tools consistent with construction work.”

Mr. Abrego Garcia, who had an expired license, told the officers that he and his passengers had been in St. Louis for the past two weeks doing construction work, according to the indictment. He was let off with a warning.

But a subsequent investigation, prosecutors said, revealed that Mr. Abrego Garcia’s cellphone and license plate reader data showed he had been in Texas that morning and nowhere near St. Louis for the previous weeks.

The project to link Los Angeles and San Francisco with a high-speed train that could make the trip in two hours and 40 minutes has already been scaled back numerous times, as costs spiraled and construction schedules faced repeated delays. Until now, however, the California High-Speed Rail Authority always had enough money in the bank to take incremental steps forward.

But over the last four years, the state has drawn down almost all of a $9 billion bond that voters approved in 2008. Losing the federal grants will put the project on a near starvation diet to complete even the limited, 171-mile initial segment in the Central Valley, linking Merced and Bakersfield, both of which are far from the state’s major population centers.

“I don’t think we are going to see electric trains running on track from Merced to Bakersfield for a long, long time,” said Louis Thompson, a railroad veteran who spent more than a decade as chairman of a state-appointed peer review panel for the rail project. “Not in 10 years with no federal money. This is reality, and reality is painful.”

If the Transportation Department moves forward with terminating the grants next month, as it has said it intends to do, it is likely that California will file suit to challenge the decision, a case that could drag on for years.

Even if the political landscape changes after President Trump leaves office and a future president delivers a new bundle of cash, it would take years from then to issue contracts for electrical systems and high-speed trains. Delivery and testing of those items would take years more.

State officials said this week that they would press on, relying on state funding as they have for most of the project’s history. At the slower pace required, the project becomes even more vulnerable to annual inflation, sending total costs higher.

The plan as originally envisioned called for deploying 220-mile-per-hour trains between the state’s two largest population centers at a cost of $33 billion by 2020.

Today, building the full system is a distant goal and could cost as much as $128 billion if it ever happens.

The initial segment in the Central Valley will cost up to $35 billion, more than the original estimate for the entire system. Even if the federal grant is not terminated, the initial segment would still have a funding shortfall of about $7 billion.

A lengthy compliance review by the Federal Railroad Administration this week made nine findings that the project was not complying with grant agreements, noting that it had failed to meet deadlines, incurred significant change orders and reported ridership estimates that exceeded what was likely. It said there was no “viable path” to completing the initial segment in the Central Valley by a 2033 deadline set under the grant.

In reviewing $1.6 billion in change orders on construction, the agency told state officials that “the sheer volume and frequency of these change orders shows waste through an inexcusable combination of poor planning, implementation, or mismanagement of contractors, insufficient legal authority and technical expertise, and other factors.”

The high-speed rail authority rejected the criticism and said the project would continue to move forward.

“The authority strongly disagrees with the F.R.A.’s conclusions, which are misguided and do not reflect the substantial progress made to deliver high-speed rail in California,” a spokeswoman said in a statement. “We remain firmly committed to completing the nation’s first true high-speed rail system connecting the major population centers in the state.”

Authority officials also sharply disagreed with analysts’ predictions of a possible 10-year delay. They said that they believed the state would ultimately be allowed to keep the federal grants and that they would be moving ahead with a plan to lay high-speed track within the next year.

They noted that Gov. Gavin Newsom has proposed that the project continue to receive $1 billion annually from the state’s greenhouse gas program, although that money is already accounted for in the state’s current plans through 2030.

State authorities did not directly address, however, what delays the project might face if the state did, in fact, lose access to the federal money.

Many experts on the construction project said that while the state might be able to hobble along with construction under existing funding, it appeared highly unlikely that it would be able to deliver an operational train within the next decade. When the state adopted the plan for the scaled-back Central Valley system in 2019, it was supposed to start service by 2028.

In his first term, Mr. Trump terminated a $928 million grant to the project dating back to the Obama administration. California sued, but before the case went to trial, Joseph R. Biden Jr. became president and restored the grant. Still, the state had not been able to draw on the money because of milestones that had to be passed first. The funding Mr. Trump is seeking to terminate includes not only the $3.1 billion grant issued under Mr. Biden but that earlier $928 million in funding.

The authority has about $4 billion in cash on hand, mostly from its share of California’s greenhouse gas auction program. That is enough to make some progress in completing construction that is already underway along 119 miles of farmland, but hardly enough to begin operations.

“Having this money taken away could potentially mean that they won’t be able to continue to construct it, at least at anywhere near the pace and scale they’ve been at,” said Ethan Elkind, director of the climate program at the University of California, Berkeley School of Law, who has been a supporter of the high-speed rail project.

“If there is a big gap in funding, it is going to mean layoffs and stalling the project at a certain point,” he said.

Conservatives have long supported cuts to funding for California high-speed rail. Transportation Secretary Sean Duffy last week called the project a “boondoggle.”

Diana Furchtgott-Roth, a deputy assistant secretary for research at the Transportation Department during Mr. Trump’s first term, said that the system, if it is ever built, had no hope of being profitable and that people were not likely to want to use it.

She noted the substantial decline in public transportation users since the coronavirus pandemic. “They prefer driving,” she said.

The California bullet train was originally expected to carry about 100 million passengers a year, but the estimate was later slashed by two-thirds. Estimated ridership on the mini system in the Central Valley was reduced by 25 percent in recent years.

But Mr. Elkind and other supporters have said the project could improve the quality of life in California and help drive the economy. “You’re just really greatly increasing mobility and connecting the economy, and in ways that no other mode of transport really could do as efficiently, and you’re doing it all in a very low-carbon way,” he said.

The state has 30 days to respond to the Trump administration’s notice. The rail authority said in its statement that it would “fully address and correct the record in our formal response to the F.R.A.’s notice.”

Legal analysts said that if the state sues, as Mr. Newsom promised, it is not clear that the state would prevail.

The Trump administration appears to have been careful to set up a legal basis for cutting the funding, making a lawsuit challenging, some analysts said.

But Eloise Pasachoff, a Georgetown University law professor who specializes in federal grant law, noted that the proposed funding cut “comes against the backdrop of the Biden administration doing a review of the exact same project last year and awarding another $3 billion in federal grants.” California, she said, will most likely challenge the termination on many grounds, including that the administration was “arbitrary and capricious” in its decision to revoke the money.

It is not enough, she added, for the administration to assert that funding a high-speed rail system is not a policy priority. Such a decision should go back to Congress, she said.

David Freeman Engstrom, a law professor at Stanford University, said the longstanding political antagonism between California’s Democratic governor and Mr. Trump might have been a factor in the decision to pull the grant, but it was unlikely to form a basis for a successful legal challenge.

If California argues that the termination is “just an effort to get back at Governor Newsom, an enemy of the administration, I’m not sure that a court’s going to be willing to credit that argument here,” he said.

Still, he said, there appeared to be little doubt that the termination, apart from the legal issues, was seen in Washington as a way to “stick it” to Mr. Newsom.

“By returning to the high-speed rail issue, Trump is once again lifting up a powerful symbol that liberal California is the problem, not the solution, and needs to get its own house in order.”

This year’s location was decided before the 2024 election that brought Donald J. Trump back to the White House, which sits less than half a mile from where the parade’s route will culminate on Saturday.

The parade is not expected to attract as many people as organizers had hoped, with some international L.G.B.T.Q. groups deciding not to participate. Momentum for the event began to slow shortly after Mr. Trump’s inauguration.

Mr. Trump has issued executive orders restricting gender identities on travel documents and barring transgender people from serving in the military. He has also pushed the federal government to end its diversity, equity and inclusion efforts, and many private companies have followed his lead. He took over the Kennedy Center, demanding that the Washington-based arts venue stop hosting drag shows.

Just this week, Pete Hegseth, the secretary of defense, ordered the Navy to consider removing the name of Harvey Milk, the gay rights icon, from one of its ships, arguing that the name may not reflect the nation’s “warrior ethos.”

Some corporate sponsors of previous Pride parades pulled their funding this year or did not renew their financial support. Ryan Bos, the executive director of Capital Pride Alliance, said that corporate funding reached about only half of the fund-raising goal for WorldPride and that some sponsors who did offer funding asked that their logos not be prominently displayed.

Even amid this climate, the WorldPride parade, which begins at 2 p.m. on Saturday, is expected to be a joyful affair, according to its organizers. The day is scheduled to end with a performance on the Capitol Concert Stage by the actress and singer Cynthia Erivo.

The parade has named three grand marshals: the actress and trans activist Laverne Cox, the lesbian performer Reneé Rapp and Deacon Maccubbin, who helped organize the city’s first Pride parade 50 years ago outside his L.G.B.T.Q. bookstore, Lambda Rising.

Peaches Christ, a drag queen from San Francisco, has been at WorldPride this week to host a performance by the International Pride Orchestra (which was originally set for the Kennedy Center but moved to the Music Center at Strathmore in Maryland).

She said the energy at WorldPride has been “electric.”

“The vibe this year is that Pride is a protest,” she said. “The community is fired up and ready to fight.”

The decision to pull Mr. Abrego Garcia out of El Salvador and instead put him on trial in an American courtroom could provide an offramp for the Trump administration, which had bitterly opposed court orders requiring the government to take steps to return him after his wrongful removal in March.

The 10-page indictment — filed in Federal District Court in Nashville in May and unsealed Friday — might also be an effort to save face: Bringing Mr. Abrego Garcia back to face criminal charges may allow the White House to avoid a broader legal confrontation that was increasingly headed toward questions of whether Trump administration officials should be held in contempt of court.

“Abrego Garcia has landed in the United States to face justice,” Attorney General Pam Bondi said at a news conference in Washington. “He was a smuggler of humans and children and women.”

She added, “This is what American justice looks like.”

Two people familiar with the investigation said it made a significant leap forward when an imprisoned man recently came forward offering information about Mr. Abrego Garcia, but there was concern and disagreement among prosecutors about how to proceed. In recent weeks, a supervisor in the federal prosecutor’s office in Nashville resigned over how the case was handled, these people said.

Ms. Bondi went on to level accusations against Mr. Abrego Garcia that were not included in the indictment, claiming that co-conspirators told investigators he had helped smuggle “minor children” and gang members during dozens of trips around the country. She linked him to more serious crimes, including murders and the abuse of women — even though he has only been charged in connection with smuggling.

She also claimed, without providing evidence, that his seemingly law-abiding life in Maryland as a contractor, father and husband was a cover for a criminal activities spanning nine years. Ms. Bondi, who spearheaded the administration’s public relations campaign to discredit him during the court battle, predicted he would be convicted and returned to El Salvador for imprisonment.

The attorney general declined to say when the Tennessee investigation into Mr. Abrego Garcia was opened. His indictment was filed more than two weeks ago, on May 21, and unsealed Friday after he arrived in the United States.

The deputy attorney general, Todd Blanche, said he believed the indictment was likely to render moot the lawsuit brought by Mr. Abrego Garcia’s family to force his release from Salvadoran custody.

Mr. Abrego Garcia made an initial appearance in federal court in Nashville later Friday, and the government moved to hold him in custody. He was detained in Putnam County jail outside the city and is expected to return to court on June 13.

Asked whether he had spoken directly with President Nayib Bukele of El Salvador to take steps to free Mr. Abrego Garcia, Mr. Trump demurred. “I don’t want to say that. But he’s returned,” he said, adding: “And he should have never had to be returned. You take a look at what’s happened with him; you take a look at what they found in the grand jury and everywhere else.”

Mr. Bukele, who had previously said he would not release Mr. Abrego Garcia, said on social media on Friday, “We work with the Trump administration, and if they request the return of a gang member to face charges, of course we wouldn’t refuse.”

Mr. Abrego Garcia’s lawyers said they welcomed their day in court and pointed out that the government’s decision to return him to the United States undercut its longstanding efforts to keep him in El Salvador.

“Today’s action proves what we’ve known all along — that the administration had the ability to bring him back and just refused to do so,” said Andrew Rossman, a lawyer for Mr. Abrego Garcia. “It’s now up to our judicial system to see that Mr. Abrego Garcia receives the due process that the Constitution guarantees to all persons.”

Ama Frimpong, the legal director for CASA, an immigrant rights group based in Maryland, described the mixed feelings of Mr. Abrego Garcia’s wife, Jennifer Vasquez Sura. She “is of course very happy that her husband is back on U.S. soil, at least as far as we know,” Ms. Frimpong said, “but of course, under very egregious and horrendous circumstances.”

Even though the Trump administration has repeatedly accused Mr. Abrego Garcia of belonging to MS-13 — which has been designated as a terrorist organization — a three-judge panel of the U.S. Court of Appeals for the Fourth Circuit ruled in April that the defendant had been deprived of his rights by being wrongly deported.

“The government asserts that Abrego Garcia is a terrorist and a member of MS-13,” the panel wrote. “Perhaps, but perhaps not. Regardless, he is still entitled to due process.”

Since the start of the case, administration officials have sought to depict Mr. Abrego Garcia, a metal worker who has lived illegally in the United States without criminal charges for years, as a member of MS-13. The charges filed against him on Friday accused him of belonging to the gang and taking part in a conspiracy to “transport thousands of undocumented aliens” across the United States.

In court papers seeking his pretrial detention, prosecutors said Mr. Abrego Garcia had been part of a trafficking conspiracy and had played “a significant role” in smuggling immigrants, including unaccompanied minors.

If convicted, Mr. Abrego Garcia could face a maximum sentence of 10 years in prison for each person he transported, the papers said, a penalty that would go “well beyond the remainder of the defendant's life.”

Mr. Abrego Garcia had been in Salvadoran custody since March 15, when he was flown, along with scores of other migrants, into the hands of jailers at the so-called Terrorism Confinement Center, a notorious prison known as CECOT. He was later moved to another facility in El Salvador.

For nearly three months, his lawyers have been trying every legal strategy to enforce court orders demanding that the Trump administration “facilitate” his release from El Salvador.

From the beginning of the case, officials have acknowledged that Mr. Abrego Garcia was wrongfully expelled to El Salvador in violation of a previous court order that expressly barred him being sent to the country. But the Justice Department, acting on behalf of the White House and the Department of Homeland Security, has not given an inch beyond that admission, saying only that if Mr. Abrego Garcia presented himself at the U.S. border, officials would “facilitate” his re-entry to the country.

Department lawyers have also spent weeks stonewalling an effort by Judge Paula Xinis, who is overseeing the case, to get answers to the question of what the White House has done, and planned to do, to seek Mr. Abrego Garcia’s freedom. The administration’s serial refusals to respond to inquiries about its own behavior in the case has so annoyed Judge Xinis that this week she allowed Mr. Abrego Garcia’s lawyers to seek penalties against the government.

According to the indictment, the case against Mr. Abrego Garcia dated to Nov. 30, 2022, when he was stopped for speeding by the Tennessee Highway Patrol on Interstate 40 East, in Putnam County. Officers determined that the Chevrolet Suburban he was driving had been altered with “an aftermarket third row of seats designed to carry additional passengers,” the indictment said.

It also noted that there were “nine Hispanic males packed into the S.U.V.”

Mr. Abrego Garcia told the officers that he and his passengers had been in St. Louis for the past two weeks doing construction work, according to the indictment. But a subsequent investigation, prosecutors said, revealed that Mr. Abrego Garcia’s cellphone and license plate reader data showed that he had been in Texas that morning and nowhere near St. Louis for the past weeks.

Moreover, the indictment said, none of the people in the vehicle “had luggage or even tools consistent with construction work.”

Prosecutors said that the traffic stop in Tennessee was not the first time that Mr. Abrego Garcia had engaged in alleged immigrant smuggling, which they said was his “primary source of income.” They added that he had transported about “50 undocumented aliens” a month across the country for several years.

Jazmine Ulloa and Annie Correal contributed reporting.

The talks come at a fragile moment for the global economy, which has been slowed by uncertainty and supply chain disruptions. The United States in April paused some of the tariffs that Mr. Trump imposed on dozens of countries to provide time for trade negotiations.

Those levies, as well as steep import taxes on Chinese goods, were thrust into further uncertainty in late May, when a U.S. trade court deemed them illegal. The tariffs, however, currently remain in place while an appeal process unfolds. As the U.S. delegation meets in London, the Trump administration has a deadline to make its case to a federal appeals court for why the tariffs should continue.

The announcement of Monday’s talks came a day after Mr. Trump held a call with Xi Jinping, China’s president, that was intended to break a deadlock that threatened to derail a trade truce that the countries reached in early May in Geneva. Under that truce, the United States reduced Mr. Trump’s tariff on Chinese imports to 30 percent from 145 percent, and China lowered its import duty on American goods to 10 percent from 125 percent.

But in recent weeks, the tension between the two countries returned, tied to mineral exports to the United States, which China had recently halted. The Trump administration also proposed a plan to revoke visas for Chinese students associated with the Communist Party or studying in critical fields.

Mr. Bessent, who has been leading the negotiations with China for the United States, recently acknowledged that the talks had stalled and suggested that it would be up to the two leaders to get them back on track.

Then, last week, Mr. Trump said on social media that China had “violated” the agreement that was brokered in Switzerland. Beijing rejected that notion, accusing Washington of severely undermining the trade truce.

The back and forth continued this week when Mr. Trump wrote on social media on Wednesday that Mr. Xi was “VERY TOUGH, AND EXTREMELY HARD TO MAKE A DEAL WITH.”

A day later, however, Mr. Trump said that his 90-minute call with Mr. Xi had been productive.

“I just concluded a very good phone call with President Xi, of China, discussing some of the intricacies of our recently made, and agreed to, Trade Deal,” Mr. Trump said, adding that it “resulted in a very positive conclusion for both Countries.”

Those jobs include the people who specialize in hurricane forecasts and issue warnings about tornadoes and flash floods, as well as the employees who physically maintain things like weather models or launch weather balloons.

“Weather forecasting is not partisan,” said Representative Mike Flood, Republican of Nebraska, one of the bill’s bipartisan sponsors. “Everyone supports the National Weather Service. Everyone relies on them, whether they realize it or not.”

The Weather Service has suffered from short staffing for years, long before the Trump administration’s cuts, but that became more severe this spring, as hundreds more employees began retiring or were forced out.

At the same time, the country has faced a nonstop pace of deadly and expensive weather disasters, including the California wildfires, several tornado outbreaks and severe hailstorms. For the first time in the agency’s history, some forecasting offices no longer had enough staff members to operate overnight, and others had to curtail the twice-daily launches of weather balloons, which collect data on atmospheric conditions that feed into forecast models.

The bill comes at the start of an Atlantic hurricane season that is predicted to bring more storms than usual. Some observers have expressed concerns about understaffed offices and worker fatigue affecting forecasts.

Mr. Flood said he hoped granting the National Weather Service the authority to hire directly would ensure that shortages could be addressed more quickly than is possible in the current process, in which hiring runs through its parent agency, the National Oceanic and Atmospheric Administration.

NOAA declined to comment on the pending legislation.

The bill may pave the way for the agency’s director, Ken Graham, to implement a-planned restructuring. Mr. Flood said he hoped the legislation would give Mr. Graham “some latitude” to modernize.

Also this week, NOAA said the Weather Service had been granted an exemption to Mr. Trump’s governmentwide hiring freeze, which would allow it to hire 126 people in positions around the country in an effort to “stabilize” the agency. The Weather Service has also been shuffling forecasters and other employees between offices on short-term assignments to fill staffing gaps.

The bill’s other sponsors include Representative Frank Lucas, Republican of Oklahoma, as well as Democratic Representatives Jared Moskowitz of Florida, Jimmy Panetta of California, and Eric Sorensen of Illinois. All represent states that have been hit by severe weather this year.

“Severe weather affects both blue states and red states, and ensuring Americans have access to reliable and accurate weather forecasting is something everyone should support regardless of their political affiliation,” said Mr. Sorensen, who is the only meteorologist in Congress. “I’m grateful for Congressman Flood’s partnership on bipartisan legislation that will help fully staff National Weather Service offices across the country during severe weather and hurricane season.”