WASHINGTON (Reuters) – U.S. President Donald Trump is ramping up his search for a new chief for the U.S. central bank, meeting with former Federal Reserve Governor Kevin Warsh and three others and promising a decision next month.

“I’ve had four meetings for Fed chairman and I’ll be making a decision over the next two or three weeks,” Trump told reporters on the White House South Lawn.

Trump has previously suggested he may reappoint Fed Chair Janet Yellen to the post. Jerome Powell, one of the current governors on the Fed’s board, also met with Trump earlier this week about the Fed job, the Wall Street Journal reported on Friday. Trump on Friday did not provide details on his meetings.

A new Fed chair would take the helm as the central bank eases well away from crisis-era policies in response to a strengthening economy and falling unemployment, though inflation still lingers below the Fed’s 2-percent goal.

Under Yellen, the Fed has raised interest rates and launched a plan to shrink its $4.5 trillion balance sheet. Much of the latter was accumulated through a controversial bond-buying program that Yellen said helped the economy avert an even deeper downturn.

Her term as chair expires in February.

Warsh was a Fed governor between 2006 and 2011 and resigned from the board because of his opposition to the bond-buying program. He has called for a revamp of how the Fed makes monetary policy, saying it needs “fresh air” from markets and from the “real economy.”

Treasury yields spurted higher on news of the Trump meetings; Warsh is viewed as more of a hawk than Yellen.

”He’s definitely more hawkish on the spectrum. He is quite a contrast to Yellen. It does seem he is the front-runner even though it’s not a sure thing he will be nominated,” Gennadiy Goldberg, interest rates strategist at TD Securities in New York, said of Warsh.

As recently as July, Trump had not ruled out reappointing Yellen, telling the Wall Street Journal that he liked her demeanor and desire to keep interest rates low.

In addition to Warsh and Powell, Stanford University economist John Taylor’s name also has been floated as a contender.

Powell specialized in financial regulatory matters during his five years on the Fed Board of Governors, which is led by the Fed chair.

There has also been speculation that Trump could turn to his top economic aide, Gary Cohn, for the Fed chair position.

A Fed spokesman declined to comment on the process while Warsh and Taylor did not respond to requests for comment.