Pierre Yared, the acting head of the White House Council of Economic Advisers, is stepping down and returning to Columbia University, President Donald Trump said Tuesday. Trump did not specify a final date for Yared’s departure.

“Since September, my Council of Economic Advisers has been led by the very highly respected Professor Pierre Yared, of Columbia University, as he and his team of ‘Brainiacs’ at the CEA have worked around the clock to Make America WEALTHY Again—with Great Success!” Trump wrote on social media.

Yared, a professor of international business at Columbia University, had been serving as acting CEA chair since Trump appointed Stephen Miran to the Federal Reserve Board of Governors last September. Miran had held the unusual dual role of Fed governor and CEA chair for months before stepping down from the CEA earlier this year. He left the Fed in May to make room for Kevin Warsh, whom Trump appointed as Fed chairman.

The CEA is a White House office that advises the president on economic policy. Trump nominated Christopher Phelan, a University of Minnesota professor, as the next permanent CEA chair in April. Senators considered Phelan’s nomination during a committee hearing last week.

Yared did not immediately respond to a request for comment.