Nick Ayers, who was seen as the favorite to replace John Kelly as White House chief of staff, took himself out of the running for the job on Sunday.

In a tweet, Ayers said he would be leaving his job as chief of staff to Vice President Mike Pence by the end of this year to work on President Donald Trump's re-election campaign.

White House aides told USA TODAY that Trump and Ayers had discussed Ayers taking the job but could not agree on how long he would serve in the role. Ayers, 36, has a young family – which includes 6-year-old triplets – and did not want to make a long-term commitment to the grueling job, the officials said.

Ayers thanked both Trump and Pence for hiring him to serve in the White House. "I will be departing at the end of the year," he wrote on Twitter.

Later Sunday, Trump tweeted he had "really great" candidates for the position.

"I am in the process of interviewing some really great people for the position of White House Chief of Staff," Trump said. "Fake News has been saying with certainty it was Nick Ayers, a spectacular person who will always be with our #MAGA agenda. I will be making a decision soon!"

Kelly, who has clashed with Trump on scheduling and organization of the White House, is leaving the post at the end of the year, the president announced Saturday.

The shakeup comes as the president prepares to confront a Democratic-controlled House of Representatives starting next month while revelations and indictments continue to pour out of special counsel Robert Mueller's investigation into Russian interference in the 2016 presidential election.

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Ayers, a political consultant who rose rapidly through Republican ranks, was seen as someone who could bring more political experience to the chief of staff job than Kelly had.

The new chief of staff will take on the challenge of setting Trump's schedule, supervising many of his aides and controlling access to the Oval Office – difficult tasks in a White House where the president often catches his own staff off guard with impromptu meetings and phone calls and major policy changes announced on Twitter.

The top remaining candidates to replace Kelly are considered to be Treasury Secretary Steven Mnuchin, budget director Mick Mulvaney and trade representative Robert Lighthizer.

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