WASHINGTON — Budget director Mick Mulvaney headed to the White House Friday expecting to attend a meeting on federal budget issues, according to a source close to him. Instead, by the end of the day, he would — at least temporarily — become President Donald Trump’s third chief of staff.

Trump, who had been rebuffed by at least two potential replacements to the outgoing chief of staff, Gen. John Kelly, hastily settled on Mulvaney as acting chief after initially refusing vice presidential chief of staff Nick Ayers' request to serve in a similar interim capacity.

The president made the decision after polling several members of his Cabinet, including at a Thursday evening White House holiday party, according to sources. All of them expressed approval of Mulvaney, also a former congressman.

Trump was also desperate to end the storyline that no one wanted to be his chief of staff, with other individuals reportedly on his short list — including Rep. Mark Meadows of North Carolina — publicly rejecting the potential job, a source told NBC News. On Friday morning, White House officials eagerly floated the idea that former New Jersey Gov. Chris Christie was the front runner, only to have Christie publicly reject it by midday.

It was Mulvaney who asked for an “acting” title, reflecting his desire to occupy the job for a limited period of time, according to two sources.

Mulvaney, who understood the president was in a jam and felt he didn’t have much choice, told Trump he would prefer to serve no longer than six months, according to the source close to Mulvaney. Another source confirms that Mulvaney made clear his intentions to serve for a limited period of time, given his general reluctance to accept the position.

Meghan Burris, a spokeswoman for the Office of Management and Budget, which Mulvaney heads, told NBC News that Mulvaney "both likes and respects the president, and he likes working for him.”

“More importantly,” Burris added, “director Mulvaney believes in the president because he is working every day to lift up millions of Americans and stands up for our great country.”

The White House did not immediately respond to a request for comment. In a tweet Friday, Trump maintained that there were "many" candidates who wanted the position.

For the record, there were MANY people who wanted to be the White House Chief of Staff. Mick M will do a GREAT job! — Donald J. Trump (@realDonaldTrump) December 15, 2018

Mulvaney, a former South Carolina lawmaker, enjoys good working relationships with many West Wing staffers as well as former chief economic adviser Gary Cohn, who remains close to presidential advisers Jared Kushner and Ivanka Trump. One White House staffer described a feeling of “relief” that Trump picked Mulvaney over some other potential choices.

A source familiar with the president’s thinking says Trump wanted his next chief of staff to be more “public-facing” than Gen. Kelly.

Mulvaney has in the past been a visible figure on cable news. Sources also say Trump thinks Mulvaney’s experience as a former congressman will help him navigate the expected oversight demands of House Democrats.

But another source close to Mulvaney said he is not interested in being on the front lines of defending the president on cable news and wants to “keep his head down.”