Mick Mulvaney will become the acting White House chief of staff at the end of the year, President Donald Trump announced in a tweet on Friday.
Mulvaney will not resign as director of the Office of Management and Budget while he is acting White House chief of staff, White House press secretary Sarah Sanders said Friday evening. OMB Deputy Director Russ Vought will handle day-to-day operations for the office, Sanders said in a statement.
A senior administration official said there is "no time limit" for Mulvaney to remain in the top White House post.
Mulvaney could lose the "acting" part of his title if things go well, according to another senior administration official.
The chief of staff job is "his to lose," this administration official told CNN.
The President's decision to appoint Mulvaney as his chief of staff began to materialize around 4 p.m. Friday afternoon, this official said.
Trump had been marinating on this idea throughout the day and ultimately decided to pull the trigger because the speculation and bowing out of candidates had begun to get out of hand.
The decision, the official said, was driven by a desire inside the West Wing to put an end to the immense speculation of the last week and to give what had become a chaotic process "a certain degree of finality."
A source familiar with the situation told CNN's Jim Acosta that the President wants Mulvaney to remain OMB director while serving as acting chief of staff. A White House official had earlier told CNN that Mulvaney was going step down from his OMB role and Vought would take over in an acting capacity.
Mulvaney, a conservative former South Carolina congressman, will be the third chief of staff in under two years to take on the task of running a White House besieged by a drumbeat of investigations and the expectation of more as Democrats take over the House of Representatives next month. Mulvaney's elevation to the role of chief of staff comes a week after Trump announced that his current chief of staff, John Kelly, will leave his post at the end of the year.
"I look forward to working with him in this new capacity as we continue to MAKE AMERICA GREAT AGAIN!" Trump tweeted of Mulvaney. "John will be staying until the end of the year. He is a GREAT PATRIOT and I want to personally thank him for his service!"
Trump appointed Mulvaney to the position in an acting role about a week after Vice President Mike Pence's chief of staff Nick Ayers declined Trump's offer to become chief of staff, refusing to agree to a two-year time commitment the President had requested. Their inability to come to terms sent Trump scrambling this week to reassess his list of contenders for chief of staff, leading to a search during which one candidate after the next withdrew from consideration or agreed with the President to take themselves out of the running.
While Mulvaney remained in the running this week, he had also indicated that he was not interested in the chief of staff role, with a source close to him instead indicating Mulvaney was interested in moving up to lead the Treasury or Commerce departments.