WASHINGTON, May 14 (Reuters) - U.S. Federal Reserve Governor Stephen Miran on Thursday said he would resign his seat on or shortly before Kevin Warsh is sworn in as the Fed's next chair, a necessary step since there is no other open seat on the seven-member board for Warsh to fill and Miran's term had technically expired in January.

In a letter to President Donald Trump released by the Fed, Miran recounted the arguments he made in favor of lower interest rates, familiar from his many public appearances and the dissents he registered at every Fed policy meeting since joining the central bank's board last September while on leave from the Trump administration.

Warsh's nomination to the Fed was confirmed by the U.S. Senate this week, with his swearing-in still to be scheduled.