President Donald Trump said Wednesday he will fire Federal Reserve Chair Jerome Powell if Powell does not leave office voluntarily once a successor is confirmed, escalating a months-long confrontation over the central bank's independence less than a month before Powell's chairmanship expires on May 15.

The threat, delivered during a Fox Business interview, sharpens a collision between the White House and the Fed at a moment when inflation is climbing, oil prices are surging because of the Iran war and global policymakers are gathering in Washington for the International Monetary Fund's spring meetings. Former Fed Chair Janet Yellen, speaking the same day, warned that the president's pressure campaign on interest rates resembles the conduct of an unstable government.

The president's words

Trump framed the potential firing as a last resort. "Then I'll have to fire him," the president said. "If he's not leaving on time — I've held back firing him. I've wanted to fire him, but I hate to be controversial. I want to be uncontroversial."

Powell's term as chair ends May 15, and Trump has nominated former Fed Governor Kevin Warsh to replace him. But Powell has two years remaining on his separate term as a Fed governor, which runs until January 2028. Most past chairs have departed the central bank entirely after being replaced, but Powell has declined to say whether he will do so.

Powell's exit has grown more complicated because of a federal investigation into the renovation of the Fed's headquarters building. U.S. attorney for the District of Columbia Jeanine Pirro attempted to issue a subpoena to Powell for information about the project but was rebuffed by a judge, a decision Pirro said she would appeal. Sen. Thom Tillis, R-N.C., has said he will block Warsh's nomination from leaving the Senate Banking Committee until the probe concludes.

Trump said the investigation must continue. "What they've done to that so it is probably corrupt, but what it really is is incompetent, and we have to show the incompetence of that," the president said.

Yellen fires back

Yellen, who chaired the Fed from 2014 to 2018 and later served as Treasury secretary under President Biden, delivered her sharpest public criticism of Trump's approach to monetary policy at an HSBC investor summit in Hong Kong.

"How often does the president of a developed country express the view that the interest rate should be set to reduce the debt service cost? This is what you hear in a banana republic," Yellen said. She argued that inflation can spiral when central banks fall under the control of politicians seeking to borrow more cheaply.

Yellen also questioned whether Warsh, whom Trump has said he is confident will deliver lower rates, commands enough respect among Fed governors to shift policy. Comparing Warsh with former Fed Chair Alan Greenspan, she said Greenspan "was very much respected for his economic expertise." Of Warsh, she added: "I don't think that Warsh walks in with that level of credibility."

The broader fight

The confrontation over Powell is not isolated. Trump last year moved to replace Fed Governor Lisa Cook following accusations of mortgage improprieties, a case that has been argued before the U.S. Supreme Court and awaits a decision. The outcome could determine the legal boundaries of a president's power to remove Fed board members.

Trump has also repeatedly attacked Powell personally, calling him a "moron" and accusing him of being too slow to cut rates. The Fed last reduced its benchmark rate in December, to a range of 3.5 to 3.75 percent, but policymakers have grown cautious as the Iran conflict drives energy prices higher and feeds into broader inflation readings.

What is missing

No right-leaning or conservative commentary appeared among the sources available for this report. Republican lawmakers beyond Tillis had not publicly weighed in on the firing threat by press time.

The Senate Banking Committee has not scheduled a date for Warsh's confirmation vote. Powell has said he will remain as chair until a successor is confirmed, consistent with Fed policy, leaving open the possibility that his tenure extends beyond May 15 if the Senate does not act.