Jeff Sessions, the US Attorney General, abruptly asked the remaining 46 chief federal prosecutors left over from the Obama administration to resign on Friday, including Manhattan US Attorney Preet Bharara, who had been asked to stay on in November by then President-elect Donald Trump.
Although US attorneys are political appointees, and the request from Trump's Justice Department is part of a routine process, the move came as a surprise. Not every new administration replaces all US attorneys at once.
A Justice Department spokeswoman confirmed the resignation requests included Mr Bharara, whose office handles some of the most critical business and criminal cases passing through the federal judicial system.
Mr Bharara met with Trump in Trump Tower on November 30. After, Mr Bharara told reporters the two had a "good meeting" and he had agreed to stay on.