Four Democratic senators have asked Federal Reserve Chair Kevin Warsh to disclose all conversations he has had with President Donald Trump since taking office.

Bloomberg reported on August 19 that Senators Chris Van Hollen, Jack Reed, Angela Alsobrooks and Elizabeth Warren sent Warsh a letter urging him to release details of every conversation with Trump since he became chair in May.

The request followed reports that Trump and Warsh had spoken by phone several times since Warsh took over at the Fed. Bloomberg reported earlier this month, citing people familiar with the matter, that the two discussed Warsh's economic outlook and views in multiple conversations. Trump did not directly seek any specific monetary policy action during those calls.

The senators argued that communication between the Fed and the White House should be disclosed transparently to maintain confidence in monetary policy. In the letter, they wrote that making those discussions public was important to show the Fed remains independent of the White House and noted that Warsh himself had pledged to uphold that principle.

They also said Warsh's public schedule for his first month in office listed calls and meetings with lawmakers, White House officials and private-sector economists, but did not include any contact with Trump.

"As head of an independent agency, the Fed should be transparent about conversations with the president, and previous chairs have also recognized that," the senators wrote.

The issue has emerged as Trump continues to press the Fed to cut interest rates. The White House also resumed efforts this month to remove Fed Governor Lisa Cook.

News of the contacts between Trump and Warsh has raised the prospect of a sharper political fight over central bank independence as the Fed makes future monetary policy decisions.