WASHINGTON — President Trump announced on Tuesday that he had ousted Secretary of State Rex W. Tillerson and will replace him with Mike Pompeo, now the C.I.A. director, ending the 14-month tenure of the nation’s chief diplomat who repeatedly had found himself at odds with the White House on a variety of key foreign policy issues.
“We were not really thinking the same,” Mr. Trump told reporters at the White House, explaining his decision to replace Mr. Tillerson.
He added: “Really, it was a different mind-set, a different thinking.”
Mr. Tillerson found out he had been fired before dawn, shortly after his flight returned from a weeklong trip to Africa, said Steve Goldstein, the under secretary of state for public diplomacy. There was no indication during the five-nation visit that Mr. Tillerson’s departure was imminent; Mr. Goldstein said on Tuesday morning that the secretary had been expected to remain in office for the foreseeable future.
The president did not personally call Mr. Tillerson, and Mr. Goldstein said he did not know how the chief diplomat learned he had been fired.
Mr. Trump announced his decision on Twitter:
Mr. Tillerson has been out of favor with Mr. Trump for months but had resisted being pushed out. His distance from Mr. Trump’s inner circle was clear last week when the president accepted an invitation to meet with Mr. Kim, to Mr. Tillerson’s surprise.
Mr. Trump said Mr. Pompeo “has earned the praise of members in both parties by strengthening our intelligence gathering, modernizing our defensive and offensive capabilities, and building close ties with our friends and allies in the international intelligence community.”
“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,” the president continued, in a written statement distributed by the White House. ”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.”
Mr. Pompeo, a former congressman, has become a favorite of Mr. Trump’s, impressing the president with his engaging approach during morning intelligence briefings. But he also, at times, has been at odds with the president — including agreeing with a C.I.A. assessment about Russia’s interference in the 2016 elections.
In picking Ms. Haspel to succeed Mr. Pompeo at the C.I.A., Mr. Trump opted for continuity rather than bringing in an outsider. At one point last fall, Senator Tom Cotton of Arkansas, one of the president’s closest Republican allies on Capitol Hill, had been tentatively tapped as the front-runner to run the agency if Mr. Pompeo moved up, but the idea later faded.
Mr. Tillerson, a former chief executive of the oil giant Exxon Mobil, had once been viewed as an intriguing, if unorthodox, cabinet choice. He had deep experience with Middle Eastern potentates, and knew President Vladimir V. Putin of Russia through Exxon’s extensive efforts to explore for oil in Russia.
But the early enthusiasm for bringing a business sensibility to the State Department faded fast, as Mr. Tillerson seemed overwhelmed by the diplomatic challenges before him and isolated by career foreign service officers whom he often froze out of the most important debates.
His profound disagreements with the president on policy appeared to be his undoing: Mr. Tillerson wanted to remain part of the Paris climate accord; Mr. Trump decided to leave it. Mr. Tillerson supported the continuation of the Iran nuclear deal; Mr. Trump loathed the deal as “an embarrassment to the United States.” And Mr. Tillerson believed in dialogue to resolve the North Korean nuclear crisis, but Mr. Trump repeatedly threatened military options.
Veteran diplomats said they could not remember a time when a president so regularly undermined his secretary of state so brazenly in the midst of a tense situation. Richard N. Haass, the president of the Council on Foreign Relations, who served many Republican presidents, last fall urged Mr. Tillerson to quit.
“Rex Tillerson has been dealt a bad hand by the Potus & has played it badly,” Mr. Haass wrote in a post on Twitter, using the acronym for president of the United States. “For both reasons he cannot be effective SecState & should resign.”
Veteran diplomats, who had seen in the gravelly voiced Mr. Tillerson a man of stature, experience and great wealth whom they hoped the president would respect and heed, eventually turned against him as he expressed more interest in shrinking the department than expanding American influence.
While other cabinet officers made their goals plain, Mr. Tillerson never set clear diplomatic priorities other than to pursue Mr. Trump’s slogan of “America First,” a term he never really defined. In an odd admission more than eight months into the job, Mr. Tillerson told employees in September that his top priority was to make the State Department more efficient. Yet he never fully addressed what diplomats should be doing with that greater efficiency.
Congress rebelled, declining to endorse his suggested 30 percent cuts in the State Department’s budget. But the message of his tenure seemed clear: At a moment when money was being poured into the Pentagon and intelligence agencies, diplomacy seemed less valued than at any time in recent American history.
The turning point for Mr. Tillerson came when NBC News reported that he had called the president a “moron,” leading him to take the extraordinary step of holding a news conference to affirm his support for Mr. Trump and insist that he had never considered resigning.
During a trip to Beijing in September, Mr. Tillerson told reporters that he already had “a couple, three” lines into North Korea to get communication started with the United States. Mr. Trump erupted the next morning, and denigrated the effort on Twitter by saying Mr. Tillerson was “wasting his time trying to negotiate with Little Rocket Man.”
“Save your energy Rex,” he added, “we’ll do what has to be done!” Mr. Trump later said he wished his secretary of state were tougher. The Chinese were left to wonder why Mr. Trump sent an emissary whose message the president did not believe in.
Part of the reason for Mr. Trump’s eruption then was that Mr. Tillerson’s suggestion of secret talks with North Korea surprised President Moon Jae-in of South Korea, who called the White House to complain, according to people with knowledge of the exchange. That Mr. Tillerson failed to take into account Seoul’s possible reaction was one of several embarrassing stumbles, arising from his own inexperience and decision to insulate himself from the department’s diplomatic corps.
With his ousting, Mr. Tillerson joins a long list of Trump administration appointees who have left or been fired, including the president’s first national security adviser, chief of staff, chief strategist, press secretary, two White House communications directors and secretary of health and human services.
Mr. Tillerson had some successes, including the growing international isolation of North Korea and improved ties between Saudi Arabia and Iraq. But he is likely to go down as among the least successful secretaries of state in history, and one big reason was his poor management of his relationship with Mr. Trump.
Although Mr. Tillerson spent his first months on the job getting to know Mr. Trump at lunches, dinners and White House get-togethers, the two never established a comfortable rapport.
Once the head of the Boy Scouts of America, Mr. Tillerson was outraged when the president spoke to the Boy Scouts in July and turned it into a political event. When Mr. Trump declined to denounce white nationalists who paraded in Charlottesville in August, Mr. Tillerson made it clear that Mr. Trump “speaks for himself” — not his secretary of state.
The growing distance between the men was on clear display during Mr. Trump’s trip to Asia in November, when Mr. Tillerson visited the prison that once housed Senator John McCain, a Republican from Arizona who is a frequent critic of the president.
But perhaps the most puzzling part of Mr. Tillerson’s tenure was his poor oversight of the State Department. As a former top business executive, his managerial skills were thought to be his chief asset.
But he failed to quickly pick a trusted team of leaders, left many critical departments without direction and all but paralyzed crucial decision makingin the department.
He approved one global conclave in Washington just eight days before the event was to start, ensuring that few leaders from around the world were able to attend. He rarely sat for comprehensive briefings with many of his top diplomats and often failed to consult the State Department’s experts on countries before visiting.
Foreign diplomats — starting with the British and the French — said Mr. Tillerson neither returned phone calls or, with much advance warning, set up meetings with his counterparts. Strategic dialogues with many nations, including nuclear weapons powers like Pakistan, were ended without explanation.
The State Department’s policymaking process devolved into conversations between Mr. Tillerson and a lone top aide, neither of whom had much experience or knowledge about many of the countries they discussed.
Mr. Tillerson became so isolated that even top administration officials like Mr. Pompeo and allies like Condoleezza Rice, the former secretary of state whose recommendation was crucial to his selection, had trouble penetrating a phalanx of staff to speak to him directly.
“The relationship between top management and the bulk of the State Department was toxic,” said Ambassador James F. Jeffrey, a former senior diplomat and fellow at the Washington Institute who once worked with Mr. Tillerson. “And that was a total mystery because the people at the State Department would work for the devil if he is advancing American interests, which Mr. Tillerson was.”