President Donald Trump has fired Secretary of State Rex Tillerson and will replace him with CIA Director Mike Pompeo.

Pompeo will be replaced at the CIA by Gina Haspel, who will be the first woman to lead the agency.

“Mike Pompeo, Director of the CIA, will become our new Secretary of State. He will do a fantastic job! Thank you to Rex Tillerson for his service! Gina Haspel will become the new Director of the CIA, and the first woman so chosen. Congratulations to all!” Trump wrote on Twitter Tuesday morning.

But a statement from a State Department official, Undersecretary for Public Diplomacy Steve Goldstein, added new context to Trump’s announcement when he said less than an hour after Trump’s tweet that Tillerson was unaware of these personnel changes, and “had every intention of remaining because of the tangible progress made on critical national security issues.”

“The Secretary did not speak to the President this morning and is unaware of the reason, but he is grateful for the opportunity to serve, and still believes strongly that public service is a noble calling and not to be regretted,” said Goldstein. “We wish Secretary-Designate Pompeo well.” As of Tuesday afternoon, the State Department had announced Goldstein would no longer serve in his position.

Speaking at the White House briefing room Tuesday afternoon, Tillerson said Trump had called him around noon to discuss the changes. But Trump tweeted the news at 8:44 A.M. Eastern Time.

A Senior White House official said that Trump wanted to have a new team in place before he began negotiations with North Korean Leader Kim Jong Un. He also wanted the new team for various trade negotiations.Tillerson said Tuesday in the White House briefing room that he will immediately begin designating his duties to Deputy Secretary of State John J. Sullivan, and his last official day will be March 31. The Washington Post first reported the news, and said that Trump had asked Tillerson to resign last Friday.

Pompeo, a graduate of West Point and Harvard Law School, served in the House of Representatives for over 5 years before Trump nominated him to head the CIA. In an official statement released by the White House, Trump praised Pompeo’s work with the CIA and expressed confidence in his ability take the reins at Foggy Bottom and push forward his policy priorities. “I have gotten to know Mike very well over the past 14 months, and I am confident he is the right person for the job at this critical juncture. He will continue our program of restoring America’s standing in the world, strengthening our alliances, confronting our adversaries, and seeking the denuclearization of the Korean Peninsula.”

Trump concluded that statement by thanking Tillerson for his service “ A great deal has been accomplished over the last fourteen months, and I wish him and his family well.” Speaking with reporters later Tuesday morning, he said he thinks Tillerson will be “happier” once he is no longer in the position. “I think Rex will be much happier now But I really appreciate his service. But with Mike we’ve had a very good chemistry right from the beginning,” said Trump.

TIllerson, who was previously CEO of Exxon Mobil, is President Trump’s first Secretary of State. Although he has outlasted multiple other key members of Trump’s administration, his tenure is historically short compared with his immediate predecessors. The last three first-term secretaries of State — Warren Christopher under Bill Clinton, Colin Powell under George W. Bush and and Hillary Clinton under Barack Obama — all stayed in their positions for the entire first term. Since 1949, only Alexander Haig, who served under President Ronald Reagan for nearly 18 months, has lasted less than three years in the position.

And Tillerson’s tenure has also been accompanied by a series of disputes and reports of internal fighting with the President. At one point, Tillerson found himself defending a report that he had called Trump a “moron,” but stopped short of an official denial.

“I actually got on well with Rex,” Trump said Tuesday, “but it was a different mindset.”

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Write to Alana Abramson at Alana.Abramson@time.com.