WASHINGTON -- Jerome Powell said Wednesday that he plans to remain on the board of the Federal Reserve after his term as chair ends next month "for an undetermined period of time," saying the "unprecedented" legal attacks by the Trump administration have put the independence of the nation's central bank at risk.

"I worry these attacks are battering this institution and putting at risk the things that really matter to the public," Powell said in remarks at a news conference after the Fed announced its decision to keep its benchmark interest rate unchanged.

Powell's decision to stay -- the first time a Fed chair will remain on the board as a governor since 1948 -- denies President Donald Trump a chance to fill a seat on the central bank's seven-member governing board with his own appointee. The Senate Banking Committee earlier approved Powell's successor as chair, Trump appointee Kevin Warsh, on a party-line vote. Powell will continue as a Fed governor, possibly until January 2028. Warsh, if confirmed, will take a seat currently held by Stephen Miran, a previous Trump appointee, whose term ended in January.

Powell's move could make it a bit harder for Warsh to engineer the rate cuts that Trump has demanded and Warsh advocated for last year, economists say.

"It probably means it will take Warsh a little bit longer to build the consensus he is trying to build," said David Seif, chief economist for developed markets at Nomura, an investment bank.

U.S. Attorney for the District of Columbia Jeanine Pirro said on X Friday that her office was ending its probe into the Fed's extensive building renovations because the Fed's inspector general would scrutinize them instead. But she added that her office could reopen the investigation if "the facts warrant doing so."

Apparently that didn't bring Powell the closure he felt is needed.

"I'm waiting for the investigation to be well and truly over with finality and transparency," he said. "I'm waiting for that and I will leave when I think it appropriate to do so."

The Fed Wednesday left its benchmark interest rate unchanged for the third straight meeting but signaled it could still cut rates in the coming months, moves that attracted the most dissents since October 1992. Three officials dissented in favor of removing the reference to a future cut, while a fourth, Miran, dissented in favor of an immediate rate cut.

The dissents underscore the level of division on the Fed's 12-member rate-setting committee ahead of the end of Powell's term as chair on May 15.