NEW YORK — President Trump’s ambassador to the United Nations, Nikki Haley, said Tuesday that she would resign at the end of the year, marking the departure of one of the few high-profile women in the Trump administration.
Haley, a former Republican governor of South Carolina, had been an early and frequent critic of Trump, but he named her to the UN job weeks after his election. As ambassador, Haley has been an outspoken and often forceful envoy — someone whom foreign diplomats looked to for guidance from an administration known for haphazard and inconsistent policy positions — and she emerged as something of a star amid the dysfunction of the president’s first national security team.
“It was a blessing to go into the UN with body armor every day and defend America,” Haley, seated next to Trump in the Oval Office, told reporters. “I’ll never truly step aside from fighting for our country. But I will tell you that I think it’s time.”
White House staff members were caught off guard by the announcement, which Haley and Trump had kept closely under wraps. The president said Haley had informed him roughly six months ago that she wanted to take a break by the time his administration reached its second anniversary.
He said that he hoped Haley would return in a different role and that he would name her successor in the coming weeks.
“She’s done a fantastic job and we’ve done a fantastic job together,” Trump said. “We’re all happy for you in one way, but we hate to lose you.”
Speaking to reporters on Air Force One as he flew to a rally in Iowa, Trump said he was considering a list of five candidates to replace Haley, including Dina Powell, a former deputy national security adviser. Earlier he said that his daughter Ivanka “would be incredible, but it doesn’t mean I’d pick her.”
Another possibility is Richard A. Grenell, the US ambassador to Germany, who served as a spokesman for John R. Bolton, the national security adviser, when he was ambassador to the UN under President George W. Bush. Trump said he would consider Grenell but added, “I’d personally rather keep Ric where he is.”
Haley is said to have a strained relationship with Bolton, a longtime critic of the UN and a more dominant figure than his predecessor, Lieutenant General H.R. McMaster. But she has been closely allied with Ivanka Trump and her husband, Jared Kushner.
The couple held a dinner in New York months ago celebrating Haley’s tenure there, and during her appearance with Donald Trump on Tuesday, she singled them both out for praise.
“Jared is such a hidden genius that no one understands,” Haley said. “And Ivanka has been just a great friend, and they do a lot of things behind the scenes that I wish more people knew about, because we’re a better country because they’re in this administration.”
People close to Haley insisted there was nothing behind her decision other than fatigue after nearly two years in a rigorous job. She also wanted to make her decision known before the midterms to avoid the potential for an embarrassing departure if the vote were to go against the president.
Haley’s joint appearance with Trump and his effusive praise made her a rarity among departing officials, whom he often criticizes as they go out the door. But the timing irked some West Wing aides, who saw the announcement as taking attention away from the swearing-in of Justice Brett Kavanaugh and his first day at the Supreme Court.
Soon after her arrival in New York, Haley, the first Cabinet-level UN ambassador for a Republican administration since the end of the Cold War, quickly made it clear she saw the position as a steppingstone to a higher political office — a possibility that Trump may have resented.
She became a far more visible face of US foreign policy than her first boss at the State Department, former secretary of state Rex Tillerson, and Time magazine celebrated Haley’s ascendance by putting her on a cover as one of the women who are “changing the world.”
But Mike Pompeo, Tillerson’s replacement, has recently reasserted the secretary of state’s traditional role, and with Bolton a sometime antagonist, she had less of a role than at the start of the administration.
Haley, who has long been seen as a potential presidential candidate, said Tuesday that she had no intention of running in 2020, as has been speculated. Instead, she said, she plans to campaign for Trump’s reelection.
In the short term, people familiar with her thinking said, she is likely to work in the private sector and make some money.
After nearly eight years in government — six years as governor of South Carolina in addition to her time at the United Nations — Haley has at least $1.5 million in debts, including a mortgage of more than $1 million, her 2018 financial disclosure report shows.
For the moment, few Republican strategists believe that Haley is inclined to run against Trump. But those who know her believe that she is likely to run in 2024, or even in 2020 should the president not run again.
“An open presidential race is a better chance to show off her incredible political skills, rather than some quixotic primary effort,” said Matt Moore, who was the Republican Party chairman in South Carolina when Haley was governor.
The daughter of immigrants from India, Haley favored free markets and global trade and earned international attention when she was South Carolina’s governor for speaking out against the display of the Confederate battle flag in front of the state house in the aftermath of the 2015 massacre at a black church in Charleston.
During Trump’s presidential campaign, she sharply criticized his demeanor and warned what it might mean for US diplomacy — even suggesting that his tendency to lash out at critics could cause a world war.
Those disagreements continued after she joined his administration.
Haley acknowledged her policy disagreements with the president in an op-ed in The Washington Post last month when she criticized an anonymous senior administration official who wrote an opinion piece in The New York Times, describing a chaotic administration in which many of the president’s aides disagreed with their boss.
“I don’t agree with the president on everything,” Haley wrote. “When there is disagreement, there is a right way and a wrong way to address it. I pick up the phone and call him or meet with him in person.”
In December, Haley said that women who had accused Trump of sexual misconduct “should be heard, and they should be dealt with.” It was a surprising break from the administration’s longstanding assertion that the accusations were false and that voters rightly dismissed them when they elected Trump.
“I think any woman who has felt violated or felt mistreated in any way, they have every right to speak up,” Haley told CBS.
Correction: Due to a Globe error, an earlier version of this story misstated the date of President Trump’s announcement.