WASHINGTON, D.C.: A Justice Department investigation into Federal Reserve Chair Jerome Powell could end up prolonging his leadership at the central bank, complicating President Donald Trump's efforts to replace him.

Trump has nominated former Fed official Kevin Warsh to succeed Powell when his term as chair ends on May 15. But the nomination has stalled amid an ongoing DOJ probe into Powell's testimony before the Senate Banking Committee last June regarding the Fed's building renovation.

Republican Senator Thom Tillis has said he will not support any Fed nominations while the investigation remains active. With Democrats also opposed, his stance has effectively blocked the committee from advancing Warsh's confirmation.

Powell indicated that he intends to remain in his role overseeing monetary policy if no successor is confirmed in time.

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

Beyond his role as chair, Powell remains a member of the Fed's governing board until January 2028. While it is customary for former chairs to step down entirely, Powell could stay on the board, limiting Trump's ability to appoint a replacement.

Powell declined to say whether he would step down once the investigation concludes.

"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."

The situation marks an unexpected twist for Trump, who has frequently criticised Powell, and highlights the Federal Reserve's ongoing efforts to maintain its independence.

Separately, the JFK Library Foundation said Powell will receive the John F. Kennedy Profile in Courage award on May 31, citing his efforts to protect the central bank's independence "despite years of personal attacks and threats from the highest levels of government."

The DOJ investigation itself has faced setbacks. A federal judge recently dismissed two subpoenas issued by U.S. Attorney Jeanine Pirro seeking documents related to the Fed's US$2.5 billion renovation project.

"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 has said she will appeal the ruling and dismissed concerns about delays affecting Warsh's nomination.

"I don't even know who he is," she said. "Politics is not the lane I'm in right now. ... We are focused on the law."