WASHINGTON, D.C. — Sen. Thom Tillis, a Republican member of the Senate Banking, Housing and Urban Affairs Committee, said Tuesday that he will block the confirmation of Kevin Warsh as head of the Federal Reserve until the Department of Justice concludes its federal criminal probe into current Fed Chair Jerome Powell. Tillis spoke from his office in the Dirksen Senate Office Building in Washington, D.C.

Warsh is President Donald Trump's nominee to replace Powell as head of the Federal Reserve, and his confirmation hearing is scheduled for next week. He said he would not vote to confirm Warsh until the Trump administration ends the probe, a position he said he would maintain for the remaining 64 days of his Senate tenure. If Senate Democrats remain unified against the nomination, Warsh cannot be confirmed without Tillis's vote.

Tillis said Powell did nothing wrong in the federal criminal investigation and suggested that someone in the Justice Department was investigating Powell to garner favor with someone in the White House. A federal judge blocked subpoenas in the probe last month, stating that there was essentially no evidence. He said he accepts Trump's statement that the president was not involved in opening the investigation.

"Now some people can say, 'OK, Thom, you made your point. Jay Powell's term expires as chair in May, so why not go ahead and fill it?' Because I don't want to reward bad behavior," Tillis said. He called Warsh a perfect candidate but maintained his opposition to moving forward before the probe is resolved.

Trump had previously criticized Powell and threatened to fire him. Powell has not yielded to Trump's pressure to cut interest rates. Trump suggested that Tillis would not be a factor in confirming his nominees.

Tillis, who is retiring at the end of the year, said he has lost his filter. "If I were running for re-election, I'd probably use a few different words," he said. "But I just don't have to deal with that filter."