President Donald Trump announced that CIA director Mike Pompeo would be the new Secretary of State, replacing former Exxon-Mobil CEO Rex Tillerson.

“Mike Pompeo, Director of the CIA, will become our new Secretary of State. He will do a fantastic job!” Trump wrote on Twitter. “Thank you to Rex Tillerson for his service!”

Pompeo has earned Trump’s trust as Director of the CIA and has been rumored to replace Tillerson for months.

Speaking to reporters as he left the White House on Tuesday, Trump praised Pompeo as a man with “tremendous energy” and “tremendous intellect.”

“We’re always on the same wavelength. The relationship has been very good,” he said. “I think Mike Pompeo will be a truly great Secretary of State. I have total confidence in him.”

In a statement released by the White House, Trump called Pompeo the “right person for the job.”

“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,” the statement read.

Trump’s decision was sudden, as Tillerson does not appear to know why he was fired.

“The Secretary had every intention of staying because of the critical progress made in national security,” Under Secretary of State Steve Goldstein said in a statement. “The Secretary did not speak to the President 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.”

Tillerson just returned from a trip abroad to Chad and Nigeria, before cutting his trip short to refocus on North Korea. Trump’s surprise announcement took place less than four hours after Tillerson’s flight landed.

Trump told reporters that he appreciated Tillerson’s service, but said that the beleaguered Secretary of State would be “much happier now.”

Tillerson famously clashed with Trump on several diplomatic issues, even reportedly describing the president as a “fu**ing moron.”

“I want to thank Rex Tillerson for his service,” Trump said briefly in a statement. “A great deal has been accomplished over the last fourteen months, and I wish him and his family well.”

The White House said that Trump wanted a fresh approach to his administration’s diplomatic efforts, and wanted to have his team in place in time for negotiations with North Korea.

Trump also announced that Deputy Director of the CIA Gina Haspel take Pompeo’s place as Director of the CIA, the first woman to be appointed to the job.