"Special Report" anchor Bret Baier called in to "America's News HQ" Saturday to react to the news that White House Chief of Staff John Kelly is leaving his post.

President Trump on Saturday confirmed that Kelly will leave his position at the end of the year, which will bring an end to the retired four-star Marine Corps general's 17 month-long tenure in the Trump administration.

Speaking to reporters outside the White House, Trump called Kelly a "great guy" and said he will be announcing a replacement in the coming days.

"When he came in, he was a very controlling force that calmed down an undisciplined, frankly, White House," Baier said. "He made the trains run on time."

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He said that Kelly "controlled access" to Trump, which sometimes angered the president and led to reported "dust-ups" between the two in recent months.

Baier said this is the latest in a series of notable departures from the Trump administration, and although turnover is common after a midterm election, "this administration has seen more than most."

As for Kelly's legacy, Baier said the retired general served his country "tremendously" in the military, as Homeland Security secretary and as Trump's chief of staff.

"I think that people will look back and say, 'This guy really put it out for the country,'" he said.

Baier noted that Vice President Mike Pence’s chief of staff, Nick Ayers, is reportedly the front-runner to replace Kelly.

He said that Ayers, a longtime Washington political operative, could be more suited for the role as Democrats take over the House in January and Trump ramps up his re-election campaign.

"John Kelly was well-positioned to structure access, to try to get pieces of the puzzle put on the table for the president," Baier said. "[He] was not as accomplished when it came to the political ins and outs of Washington, D.C."

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