Controversy: National security adviser John Bolton gone from the Trump White House. Was he fired, or did he quit?

National security adviser John Bolton has left the Trump administration. President Donald Trump says he asked for Bolton to resign over disagreements, while Bolton insists that he left voluntarily.

What's the story?

On Tuesday morning, Trump tweeted, "I informed John Bolton last night that his services are no longer needed at the White House. I disagreed strongly with many of his suggestions, as did others in the Administration, and therefore I asked John for his resignation, which was given to me this morning. I thank John very much for his service. I will be naming a new National Security Advisor next week."

Shortly after Trump sent this tweet, Bolton tweeted, "I offered to resign last night and President Trump said, 'Let's talk about it tomorrow.'"

Seeking to reinforce this assertion, Bolton began contacting reporters, including the Washington Post's Robert Costa, to stress that he resigned on his own.

Bolton also told Costa that he would "have his say in due course" and that he had given Costa "the facts on the resignation."

ABC News's Jonathan Karl reported that Bolton had told him that Trump's assertion that he had asked for Bolton's resignation was "flatly wrong."

But the White House shot back at Bolton. In a text message to the Daily Beast, White House press secretary Stephanie Grisham said, "Last night, Potus said he wanted Bolton's resignation on his desk tomorrow AM. Bolton delivered it. Simply put, many of Bolton's policy priorities did not align w POTUS."

Bolton responded to the Daily Beast that Grisham's statement was "flatly incorrect."

New York Magazine's Olivia Nuzzia also noted on Twitter that Bolton was initially scheduled to give an early afternoon briefing at the White House shortly after Trump tweeted.

The New York Times's Maggie Haberman and CNN's Oliver Darcy both reported that Bolton felt "uncomfortable" defending Trump's foreign policy and national security decisions.

What else?

While the exact reason for Bolton's departure is not clear, CNN's Kaitlan Collins reported that "John Bolton and President Trump got into a bitter argument last night over the president's plan to host Taliban leaders at Camp David."

Haberman echoed Collins' report, tweeting, "Lots of people saying the leaks related to the Camp David meeting, including about Pence's stance, infuriated POTUS."

Trump revealed in a tweet on Sept. 9 that he had invited the Taliban to come to Camp David for talks on Sunday — just three days before the anniversary of the September 11 attacks — but canceled after they committed a terror attack in Afghanistan.

This came despite Trump slamming former President Barack Obama in 2012 for "negotiating with our sworn enemy the Taliban — who facilitated 9/11."

Trump denied in a tweet on Monday that he had overruled the objections of members of his administration to green light the Taliban meeting, calling the accusations "Fake News" created by the "Dishonest Media" to give the appearance of "turmoil in the White House of which there is none."

This story has been updated.