WASHINGTON (AP) — President Donald Trump’s top pick to replace John Kelly as chief of staff, Nick Ayers, is no longer expected to fill that role.

That’s according to a White House official who is not authorized to discuss the personnel issue by name and spoke on condition of anonymity.

Ayers is Vice President Mike Pence’s chief of staff.

The official says that Trump and Ayers could not agree on Ayers’ length of service. The father of young children, Ayers had agreed to serve in an interim capacity though the spring, but Trump wanted a two-year commitment.

The official says that Ayers will instead assist the president from outside the administration.

Ayers took to Twitter Sunday afternoon to confirm reports he will not succeed Kelly as President Trump’s chief of staff: “Thank you @realDonaldTrump, @VP, and my great colleagues for the honor to serve our Nation at The White House. I will be departing at the end of the year but will work with the #MAGA team to advance the cause.”

Thank you @realDonaldTrump, @VP, and my great colleagues for the honor to serve our Nation at The White House. I will be departing at the end of the year but will work with the #MAGA team to advance the cause. 🇺🇸 #Georgia — Nick Ayers (@nick_ayers) December 9, 2018

A person familiar with the president’s thinking tells The Associated Press that the director of the Office of Management and Budget, Mick Mulvaney, is among those under consideration to replace Kelly.

Axios’s Jonathan Swan writes President Trump is considering House Freedom Caucus chair Mark Meadows (R-NC) for the role. “Trump has also mentioned three other candidates besides Meadows, according to a source with direct knowledge,” the news outlet reports.

The president announced Saturday that Kelly would be departing the White House around the end of the year.