WASHINGTON (AP) — President Donald Trump has for months wanted to remove Jerome Powell as chair of the Federal Reserve. But instead, an investigation by one of his own officials could end up extending Powell’s time at the top of the central bank even after his term formally ends May 15.

Trump has nominated former Fed official Kevin Warsh to succeed Powell. Yet Warsh’s confirmation has been delayed by a Justice Department investigation into brief comments Powell made before the Senate Banking Committee last June about the Fed’s building renovation. Sen. Thom Tillis, a North Carolina Republican, has said he won’t vote to confirm any Fed nominees until the investigation is dropped.

With all Democrats on the committee also opposed to moving forward, Tillis’ stance has effectively blocked the committee from advancing Warsh’s nomination.

On Wednesday, Powell said he would remain as chair of the Fed’s interest rate-setting committee after his term ends if no successor has been confirmed. And he said he could stay even longer if the investigation continues.

“I have no intention of leaving the board until the investigation is well and truly over, with transparency and finality,” Powell told reporters.

In addition to his term as chair, Powell is a member of the Fed’s seven-person governing board until January 2028. Chairs typically step off the board completely when they are no longer chair, but Powell could remain on the board and deny Trump the opportunity to fill another seat.

Powell declined on Wednesday to say whether he would step down even after the investigation is completed.

“I have not made that decision yet,” he said. “I will make that decision based on what I think is best for the institution and the people we serve.”

It’s an ironic twist of events given Trump’s well-documented ire toward Powell, and reflects the success the Fed is having in protecting its independence through the courts and in Congress.

Separately, on Thursday the JFK Library Foundation said it would present the John F. Kennedy Profile in Courage award to Powell on May 31.

Powell is being awarded for “protecting the independence of the Federal Reserve … despite years of personal attacks and threats from the highest levels of government.”

By resisting the pressure, Powell “safeguarded one of the country’s most essential apolitical institutions,” the foundation said.

Last week, the DOJ investigation into Powell was severely hobbled last week when a federal court threw out two subpoenas issued by Jeanine Pirro, U.S. Attorney for the District of Columbia, that sought information from the Fed about its $2.5 billion building renovation.

“There is abundant evidence that the subpoenas’ dominant (if not sole) purpose is to harass and pressure Powell either to yield to the President or to resign and make way for a Fed Chair who will,” U.S. District Judge James Boasberg wrote.

Pirro said last week that she would appeal the decision and was unconcerned with any delays it would cause in Warsh’s ability to take over from Powell.

“I don’t even know who he is,” Pirro said of Warsh. “Politics is not the lane I’m in right now. … We are focused on the law.”