President Donald Trump on Saturday announced Chief of Staff John Kelly would leave the White House in the next few weeks after serving in the position for close to a year and a half. The president is expected to make an announcement about Kelly's replacement Monday.

"John Kelly will be leaving at the end of the year. We'll be announcing who will be taking John's place, it might be on an interim basis. I'll be announcing that over the next day or two," Trump said, CBS News reported.

Reports suggested that Kelly always had problems with some members of the Trump administration and also with members of Melania Trump’s office. In November, CNBC noted that the first lady informed Trump about Kelly repeatedly turning down requests to promote some of her staffers even as his own staff received promotions. Trump reportedly ordered Kelly to approve Melania’s requests. However, Melania's spokeswoman, Stephanie Grisham, said, "Chief Kelly and the First Lady have never clashed.”

Post Trump’s announcement Saturday, there were reports of other candidates being considered for the position. Vice President Mike Pence’s chief of staff, Nick Ayers, was the top choice. However, Ayers declined the offer and also said he will exit the Trump administration by the end of this year.

Thanking both Trump and Pence, Ayers tweeted he “will be departing at the end of the year but will work with the MAGA team to advance the cause.”

Axios reported the other person who is reportedly being considered for the position is Republican Representative Mark Meadows. He is also the chairman of the House Freedom Caucus, a congressional caucus consisting of conservative and libertarian Republican members. ​The website, citing three sources, said Trump asked people who they think could replace Kelly and also about what they think of Meadows. The report said he was considering three more people for the position.

Bloomberg News reported Acting Attorney General Matthew Whitaker as another contender for the position. The 48-year-old was appointed as acting attorney general in November after the resignation of Jeff Sessions. He was Sessions’ chief of staff before he took up the position.

U.S. Trade Representative Robert Lighthizer is also being considered for filling the role. He was sworn in as the 18th U.S. trade representative in May 2017 and is considered one of Trump’s most powerful officials. He has played a prominent role in the administration’s policy-making on issues such as the United States' economic rivalry with China as well as the future of the North American Free Trade Agreement (NAFTA).

The last name coming forward is that of Budget Director Mick Mulvaney. Newsmax reported that the former South Carolina congressman is the favorite of the White House staff and is definitely a potential candidate.

The outlet also quoted Chris Whipple, author of the book “The Gatekeepers”, as saying “A campaign manager as chief of staff to a President is a bad idea, because there is a big difference between campaigning and governing.”

Bloomberg also stated that despite rumors, one person who is not being considered for the role at the moment is Treasury Secretary Steven Mnuchin.