Fed Chairwoman Janet Yellen will lose a close ally when Federal Reserve Vice Chairman Stanley Fischerresigns next month.
Fischer joined the Fed in March 2014 after an eight-year term as the governor of the Bank of Israel.
Fischer's term was set to expire in June 2018 and his tenure on the Fed was slated to end in January 2020.
In view of the replacement of U.S. economic leadership planned by President Donald Trump, however, the likelihood that Fischer would be appointed was brought into question.
Stanley Fischer, Fed's No. 2 Official, Is Stepping Down
Mr. Trump has nominated Randal Quarles, a private-equity executive who served in the Bush administrations, for one of the three vacant Fed board slots, but has yet to name his other picks.
Fischer, 73, cited "personal reasons", for his resignation, which will take effect October 13. "Having a complete board of governors, including members with banking experience, is important as the Fed moves forward with needed regulatory reforms and critical monetary policy decisions".
The central bank is slowly raising interest rates as the economy grows and unemployment falls. It is possible that Trump will reappoint Yellen but National Economic Council Director Gary Cohn has also been floated as a possibility.
But he also said he was still considering other candidates. For more than 20 years, he was a professor at the Massachusetts Institute of Technology, where he influenced generations of economists, from former Fed Chairman Ben Bernanke to European Central Bank chief Mario Draghi. The bank is headquartered in Indiana, Vice President Mike Pence's home state.