President Donald Trump has fired Federal Reserve Governor Lisa Cook, a sharp escalation in his battle to exert greater control over what has long been considered an institution independent from day-to-day politics.

The president said he was removing Cook from the Board of Governors immediately for "cause" but it was unclear if he has the authority to do so.

I have determined that there is sufficient cause to remove you from your position,” Mr. Trump said in a letter. Her dismissal threatened to touch off a landmark legal battle over the Fed’s independence.