"I appreciate his service very much", he added.
Trump made the announcement just before heading to the The Army-Navy Game, an American college football game between the Army Black Knights of the United States Military Academy at West Point, New York, and the Navy Midshipmen of the United States Naval Academy at Annapolis, Maryland.
On the plus side, Ivanka Trump and Jared Kushner-who have bristled under Kelly's command-and-control style-are said to be pro-Ayers.
Mueller's team asked Kelly - who the network earlier reported was no longer on speaking terms with Trump - about what he remembered about Trump's attempt to fire Mueller and whether the president had tried to obstruct justice.
Kelly, 68 moved over to the White House in July 2017 to replace former Republican National Committee Chairman Reince Priebus as chief of staff.
Seventeen months in, Kelly and President Donald Trump have reached a stalemate in their relationship and it is no longer seen as tenable by either party.
In any administration, the role of White House chief of staff is split between the responsibilities of supervising the White House and managing the man sitting in the Oval Office.
"Sure, Trump says he wants him gone, and Kelly swears and leaves and says he's not coming back".
A source told Reuters last month that Trump was considering a replacement for Kelly. But Trump, according to several senior administration officials and people close to him, has so far been unable to bring himself to personally fire a retired four-star general.
The president, at the time, said that he didn't know whether Kelly would leave, but said "I like John a lot".
Developing story, check back for updates.