Washington — President Trump praised Elon Musk for his work through the White House’s Department of Government Efficiency as the billionaire’s tenure as a “special government employee” comes to an end, saying his work “has been without comparison in modern history.”

“He’s one of the greatest business leaders and innovators the world has ever produced,” the president said, with Musk standing next to him. “He stepped forward to put his very great talents into the service of our nation, and we appreciate it.”

The president said that through his work with DOGE, his cost-cutting task force, Musk and his team have overhauled the work of the federal government.

“Elon has worked tirelessly, helping lead the most sweeping and consequential government reform program in generations,” the president said.

Musk announced earlier this week on X, the social media site he owns, that he would be finishing his time at the White House and thanked Mr. Trump for “the opportunity to reduce wasteful spending,” an initiative led by DOGE.

The world’s richest man said DOGE’s mission “will only strengthen over time as it becomes a way of life throughout government.”

The president had confirmed on social media that Musk’s last day will be Friday but added the caveat that “he will, always, be with us, helping all the way.” A senior administration official said Musk was set to begin his offboarding process Wednesday night. His departure marks a return to the private sector,  and Musk will continue as an adviser to the president, the official said.

Mr. Trump said his administration is “committed” to making the cuts made by DOGE permanent and will seek codification by Congress.

“Elon’s service to America has been without comparison in modern history,” he said.

Mr. Trump also praised a recent, temporary decision from a federal appeals court that reinstated most of his tariffs imposed under an emergency powers law. A three-judge U.S. trade court panel unanimously ruled Wednesday that the 10% tariffs, levied against nearly every U.S. trading partner, were an unlawful exercise of the president’s authority. But the U.S. Court of Appeals for the Federal Circuit temporarily halted that decision while it takes more time to consider an appeal by the Justice Department.

“The tariffs are so important, and that’s why we were so happy with the decision yesterday where the tariffs continued, because without the tariffs, our nation would be in peril,” he said.

As a special government employee, Musk was limited to working 130 days in a 365-day period. His 130th day is May 30. But in his time serving as a senior adviser to the president and leading DOGE, Musk roiled Washington through his team’s unsparing cuts to the federal workforce, cancellation of billions of dollars in federal grants and contracts, and dismantling of several agencies, even if some of those actions have been blocked by the courts.

While Musk came into the second Trump administration with a lofty promise of cutting $1 trillion from the federal budget — and even wielded a “chainsaw for bureaucracy” on stage at the Conservative Political Action Conference in February — he leaves with a tally falling far short of that goal. The CEO of Tesla and SpaceX has said that DOGE’s government-slashing efforts have saved roughly $160 billion in spending, but its “wall of receipts” documenting spending cuts has contained errors. 

And an analysis from the nonpartisan Partnership for Public Service estimated that DOGE’s actions could actually cost the government $135 billion as a result of lost productivity and changes in the status of federal workers. Some have been mistakenly fired, only to be rehired again.

Still, Musk’s time has been punctuated by a series of events that showcased his closeness with the president. He participated in Cabinet meetings at the White House, traveled on Air Force One with Mr. Trump and, joined by his son “Lil X,” addressed reporters in the Oval Office. 

The president also showcased Tesla vehicles on the driveway at the White House and said he would purchase a red Model S and praised Musk during his joint address to Congress earlier this year for his work heading DOGE.

But Musk has in recent days publicly split from Mr. Trump over his sweeping domestic policy package, which the president calls his “big beautiful bill,” that passed the House last week. 

“I was disappointed to see the massive spending bill, frankly, which increases the budget deficit, not just decreases it, and undermines the work that the DOGE team is doing,” Musk said during an interview with “CBS Sunday Morning.”

An analysis from the Congressional Budget Office estimated that the tax provisions of the package, called the “One Big Beautiful Bill Act,” would increase the deficit by $3.8 trillion by 2034.

“I think a bill can be big or it can be beautiful,” Musk told CBS News, “but I don’t know if it can be both. My personal opinion.