President Donald Trump has fired Secretary of State Rex Tillerson and replaced him with CIA Director Mike Pompeo. Gina Haspel, deputy CIA director and a career CIA employee, is Trump’s pick for CIA director.

“He will do a fantastic job!” Trump tweeted of Pompeo. “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!”

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!

— Donald J. Trump (@realDonaldTrump) March 13, 2018

The Senate Foreign Relations Committee’s hearing scheduled for Thursday on the State Department’s fiscal 2019 budget request has been canceled.

The committee was supposed to hear testimony from Rex Tillerson.

Watch: Trump, Touting Pompeo’s ‘Energy,’ Says He Clashed with Tillerson on Iran Deal

Trump and Tillerson have long clashed. His ouster comes a day after Tillerson blamed Russia for an attempted murder in London that the White House said remains unsolved.

The poisonous substance used to attack former Russian spy Sergei Skripal in London “clearly came from Russia,” Tillerson said Monday. He also vowed the poisoning would “trigger a response,” saying Russia “must face consequences.”

At the White House, Press Secretary Sarah Huckabee Sanders called the attack on Skripal “reckless, indiscriminate, and irresponsible.” But she would not repeat British Prime Minister Theresa May’s statement that Russia was most likely behind it. “I think they’re still working through even some of the details of that,” she said.

Trump’s frustrations with his secretary of state have been building for months. Sanders has told reporters since early in Tillerson’s tenure that the only people who keep their jobs are those in whom the president has confidence. By Tuesday morning, Trump’s confidence in his first chief diplomat ran out.

The president has fumed that the former ExxonMobil CEO advocated a more traditional foreign policy than Trump wants for his “America first” governing approach. The duo have been on opposite sides of a number of policy debates, including Afghanistan troop levels and how to confront North Korea over its nuclear arms and long-range missile programs.

The frustration cut both ways and at times spilled into public.

In what lawmakers called a deliberate leak by the White House, The New York Times last year reported details of a White House plan to oust Tillerson and replace him with Pompeo. Though it took a few more months, that’s exactly what Trump did Tuesday morning.

The country’s top diplomat had been “undermined” and was probably too damaged to do his job effectively, said Democratic members who follow foreign policy matters.

In early October, Tillerson delivered a loyalty pledge to Trump. That followed a report that Tillerson had considered quitting in the summer and called the president a “moron” after a Pentagon meeting in July.

During the loyalty pledge, the secretary of state lavished Trump with praise, describing the president as “smart” and lauding him for holding people accountable. The former ExxonMobil boss also credited Trump for his handling of the North Korea situation. Tillerson denied ever considering stepping down at that point — but did not directly deny calling Trump a moron.

Tillerson allowed his frustrations with the president to show more publicly at times. His disgust reportedly reached a boiling point after Trump hinted at lewd tales from his past and talked politics during a speech before thousands of Boy Scouts in West Virginia over the summer. Vice President Mike Pence was deployed to calm Tillerson down amid worries that such a high-profile departure would damage the president and his administration, NBC reported at the time. (Tillerson denied it.)

The president himself has, at several points, pulled back the curtain to let the public see his differences with his hand-picked secretary of state.

On Oct. 1, amid reports Tillerson was opening direct talks with North Korea, Trump fired off several tweets indicating he had shut down his secretary of state’s efforts. Foreign policy experts said those tweets undermined Tillerson’s ability to do his job. Starting last fall, White House officials would discuss Tillerson’s continued employment only in the shortest of terms.

On Nov. 30, Trump hedged on questions about Tillerson’s continued employment.

“He’s here,” Trump said. “Rex is here.” Later that day, Sanders would only discuss Tillerson’s “future right now,” which she said was working with Trump on closing out a “strong and positive year.”

On Capitol Hill, Democratic senators who follow foreign policy matters called on the president to cease undercutting his chief diplomat and fire him if that’s what he truly wanted in the wake of the Times report.

“I don’t understand why you would put that out there and undermine our sitting secretary of State. He is now going forward completely ineffective,” Sen. Claire McCaskill of Missouri said late last year. “If you’re going to do that, you’ve got to just do it. … Does [Trump] not want to fire him? Is he afraid to fire [Tillerson]? Here’s a guy who made a lot of money saying, ‘You’re fired.’ If he’s firing him, he should fire him and immediately put somebody else in.”

Sen. Tim Kaine, who sits on the Foreign Relations Committee that would oversee confirmation hearings for any secretary of state nominee, said after one Trump-Tillerson public dustup that the president “seems to take step after step to undercut diplomacy, tweeting out negative things about the secretary’s efforts to do diplomacy.”

Tillerson is the latest in a growing list of senior Trump administration officials to leave, due either to scandals or to butting heads with the chief executive, during the president’s nearly 14 months in office.

The Trump-Tillerson spat over whether talks with Kim Jong Un’s government would work was a major one. It was also nuanced in ways that revealed different views of how to pursue America’s interests and the president’s goals abroad.

An example came on Nov. 20, when Tillerson appeared at that day’s White House press briefing to discuss Trump’s decision to slap the “state sponsor of terrorism” label back on North Korea. The secretary of state said the move was part of the administration’s broader strategy to force the North to disarm.

“I call it the ‘peaceful pressure campaign,’” Tillerson said. “The president calls it the ‘maximum pressure campaign.’ So there’s no confusion, they’re one and the same.”

But it never did seem that Trump’s and Tillerson’s foreign policy views were “one and the same.”

Tillerson’s exit follows the departures or firings of:

• National Security Adviser Michael Flynn
• FBI Director James B. Comey
• Press Secretary Sean Spicer
• Chief of Staff Reince Priebus
• Deputy National Security Adviser K.T. McFarland
• Deputy National Security Adviser Dina Powell
• Chief strategist Steve Bannon
• National security aide Sebastian Gorka
• Communications Director Anthony Scaramucci
• Deputy Chief of Staff Katie Walsh
• Communications Director Michael Dubke
• Office of Government Ethics Director Walter Shaub
• Deputy FBI Director Andrew McCabe
• Top National Security Council Middle East adviser Derek Harvey
• U.S. Attorney for the Southern District of New York Preet Bharara
• Centers for Disease Control and Prevention Director Brenda Fitzgerald
• Staff Secretary Rob Porter
• Communication Director Hope Hicks

Niels Lesniewski contributed to this report.Correction, March 13, 2018 | An earlier version of this story misstated the condition of former Russian spy Sergei Skripal. He is in critical condition after an attempted murder by poisoning.