As Elon Musk sought to reassure Wall Street analysts on Tuesday that he would soon scale back his work with the federal government, the strain of his situation was audible in his voice.

The world’s richest man said that he would continue arguing that the Trump administration should lower tariffs it has imposed on countries across the world. But he acknowledged in a subdued voice that whether President Trump “will listen to my advice is up to him.”

He was not quite chastened, but it was a different Mr. Musk than a couple months ago, when the billionaire, at the peak of his power, brandished a chain saw onstage at a pro-Trump conference to dramatize his role as a government slasher.

Back then, Mr. Musk was inarguably a force in Washington, driving radical change across the government. To the president, he was a genius; to Democrats, he was Mr. Trump’s “unelected co-president”; to several cabinet secretaries, he was a menace; and to G.O.P. lawmakers, he was the source of anguished calls from constituents whose services and jobs were threatened by cuts from his Department of Government Efficiency.

As Mr. Musk moves to spend less time in Washington, it is unclear whether his audacious plan to overhaul the federal bureaucracy will have lasting power. The endeavor has already left an immense imprint on the government, and Mr. Musk has told associates that he believes he has put in place the structure to make DOGE a success. But he has still not come close to cutting the $1 trillion he vowed to find in waste, fraud and abuse.

Mr. Trump has constrained some of Mr. Musk’s influence over the past two months, telling cabinet secretaries that they were in charge of their own agencies. But the president also told the secretaries to work with Mr. Musk and DOGE to cut spending. At the same time, Mr. Musk has fought publicly and privately against the president’s steep tariffs that have threatened the manufacturing and profits of Tesla, his car company.

Mr. Musk has told friends that he has been frustrated by the encounters he has had with Mr. Trump’s trade advisers, according to a person briefed on the conversations who spoke on the condition of anonymity to describe private discussions. The billionaire has tried to work behind the scenes to persuade Mr. Trump to abandon his draconian protectionist posture, according to two people with knowledge of their conversations.

The White House did not respond to a request for comment, and a spokeswoman for Mr. Musk declined to comment. On Wednesday, Mr. Trump said the billionaire “was a tremendous help, both in the campaign and in what he’s done with DOGE.”

“He was always at this time going to ease out,” the president told reporters in the Oval Office.

Shaun Maguire, one of Mr. Musk’s closest friends and an adviser to DOGE officials, said that he was confident the endeavor would thrive without Mr. Musk’s full-time involvement. He compared DOGE to a Falcon 9 rocket — an initial thrust of energy powers the rocket even after it has separated from its engines.

“At this point, a rocket is only a couple hundred kilometers from Earth, but it has escaped its gravity well and can travel far into the solar system,” Mr. Maguire said. “DOGE has escaped D.C.’s gravity well.”

Mr. Maguire, who was involved in interviews for Pentagon appointments during the presidential transition, said he believed that “history will judge DOGE very favorably, well beyond what is appreciated today.”

Mr. Musk has placed DOGE allies across the federal government, seeking to dismantle some agencies, including the U.S. Agency for International Development and the Consumer Financial Protection Bureau.

The New York Times has identified more than 60 employees hired to work for Mr. Musk’s effort, although some have since left the federal government. Many have worked with the billionaire in the private sector, including at least 20 who have ties to Mr. Musk’s companies. DOGE is led by Steve Davis, Mr. Musk’s top adviser and enforcer.

DOGE staff members have overridden the objections of career civil servants at the Social Security Administration and the Internal Revenue Service to access closely held data about immigrants. Inside a Social Security database, Mr. Musk’s team put into place a system to list living immigrants they claimed were criminals as dead, in an effort to cut them off from financial services and to force them to leave the country.

All told, DOGE has tried to gain entry to more than 80 data systems across at least 10 federal agencies, The New York Times found. Those data sets include personal information about federal workers, detailed financial data about federal procurement and spending and intimate personal details about the American public.

Some of Mr. Trump’s advisers have watched anxiously as Mr. Musk has taken risky political swings at agencies that tens of millions of Americans rely on.

At the Social Security Administration, rushed policy changes have led to panicked beneficiaries overwhelming field offices. And a return-to-office policy and layoffs of probationary employees at the Department of Veterans Affairs have imperiled the agency’s mental health care program and threatened its ability to conduct medical research.

Mr. Musk came into the Trump administration claiming he would find governmental cost savings so large that they sounded impossible to budget experts.

In February, the group posted an online “wall of receipts” that detailed the savings from thousands of canceled grants, contracts and office leases. But that site included claims that confused “billion” with “million,” double- or triple-counted the same cancellations and even took credit for canceling programs that ended when George W. Bush was president.

Earlier this month, at a cabinet meeting, Mr. Musk said he had so far cut $150 billion from next year’s federal budget — far less than the $1 trillion he claimed he would extract.

DOGE has triggered sharp cuts to the federal work force and to the budgets of some agencies. But it is difficult to gauge exactly how much it has saved, because DOGE’s public claims have been riddled with errors and guesswork that inflated its success.

Mr. Musk’s slashing of the government has been politically costly, but he remains in good standing with the president, according to people familiar with Mr. Trump’s views.

While some of Mr. Trump’s close aides and advisers have argued with Mr. Musk, the president still praises him at nearly every opportunity, and still invites him to hang out at his clubs and to bring along his children.

Mr. Trump has told advisers that Mr. Musk put it all on the line for him. And he feels bad about what he calls left-wing “lunatics” attacking Tesla dealerships to protest Mr. Musk’s role in the Trump administration. Mr. Trump also respects the power of Mr. Musk’s social media platform, X, even as the president retains a commercial interest in Truth Social, his own platform.

In private, Mr. Trump has occasionally indicated to associates that it might be time for Mr. Musk to move on and spend more time with his companies. But the president is unlikely to ever pressure Mr. Musk to leave, or do anything deliberate to alienate him. He remains grateful for the hundreds of millions of dollars that Mr. Musk spent to elect him in 2024, and mindful of the additional $100 million that Mr. Musk has pledged to Mr. Trump’s political operation, the associates note.

Mr. Musk is now a financial cornerstone of the Republican Party, and will keep immense influence as long as he wants to stay involved in politics.

Still, Mr. Trump has recognized problems that Mr. Musk has caused, such as a plan for him to get briefed at the Pentagon on sensitive national security matters related to China — something even the president described privately as a conflict of interest and a meeting he was not told about in advance, according to people familiar with what took place. When Mr. Trump learned of that potential session from news reports, it was the first time people close to the president could remember him expressing displeasure with Mr. Musk.

Mr. Trump has also acknowledged to advisers that Mr. Musk has stumbled as a political force — most notably with his costly long-shot effort to flip a Wisconsin Supreme Court seat. Mr. Trump, a student of public opinion, has paid attention to the billionaire’s standing in opinion polls, watchful for any signs that Mr. Musk’s deep unpopularity might transfer.

But people close to Mr. Trump have also said that Mr. Musk has been helpful as a “heat shield,” absorbing unrelenting attacks that would otherwise be aimed at the president.

On Tuesday, Mr. Musk told analysts that he planned to dial back his government work to “a day or two per week” to turn his attention back to his companies. Administration officials with knowledge of Mr. Musk’s schedule said that they have already noticed he has reduced the amount of time he spends in Washington.

By dialing back the number of days he spends working for the White House, Mr. Musk can also potentially stretch out the 130 days he is allotted as a “special government employee.”

Zach Montague, Emily Badger, Wilson Andrews and Alexandra Berzon contributed reporting.