U.S. President Donald Trump said he was considering filing a lawsuit against Federal Reserve Chair Jerome Powell for what he called “gross incompetence,” citing the cost and management of renovations to the central bank’s headquarters.

“We’re thinking about bringing a suit against Powell for incompetence,” Trump told reporters during a joint news conference with Israeli Prime Minister Benjamin Netanyahu. “These aren’t outstanding buildings. They’re just small buildings.”

“It’s gross incompetence by Powell. And it was his project,” Trump said. “The guy’s just incompetent. There’s nothing you can do about it.”

Trump had earlier threatened legal action against Powell but provided no details. He has repeatedly criticised the cost of the renovation, accusing Powell of allowing expenses to spiral.

Powell has rejected those claims, and the Federal Reserve has said the renovation was approved in 2017 and has been subject to annual budget review by the Fed’s board of governors.

Trump first appointed Powell as Fed chair during his first term. Former President Joe Biden later reappointed him to a second four-year term. Although Trump has periodically suggested firing Powell, he has indicated he will allow Powell to serve out his term, which ends in May.