President Donald Trump indicated he is likely to fire Federal Reserve Chairman Jerome Powell, a White House official said, a dramatic step that would launch a legal battle over control of the central bank and could roil financial markets.

Asian shares are mostly higher while U.S. futures slipped after President Donald Trump rocked Wall Street by saying he had “talked about the concept of firing” the head of the Federal Reserve.

President Donald Trump denied that he plans to fire Federal Reserve Chairman Jerome Powell, contradicting a senior White House official. House Republicans said Trump spoke about the plan Tuesday night.