Florida Governor Ron DeSantis has dropped out of the 2024 presidential race and endorsed Donald Trump.
The surprise video announcement comes ahead of this week’s New Hampshire Republican primary, where Mr DeSantis was polling in the single digits.
Once considered a strong nominee, Mr DeSantis said his campaign did not “have a clear path to victory”.
In response, Nikki Haley said she is now the “only one” able to beat US President Joe Biden.
Mr DeSantis said his campaign “left it all out on the field” in a nearly five-minute long video announcement on X, formerly Twitter.
“If there was anything I could do to produce a favourable outcome – more campaign stops, more interviews – I would do it,” he said, as he ended his seven-month campaign.
The Florida governor added that he was endorsing Mr Trump because it had “become clear” that “a majority of Republican primary voters want to give Donald Trump another chance”.
While Mr DeSantis acknowledged “disagreements” with Mr Trump, he said he is “superior to the current incumbent, Joe Biden”.
“That is clear,” he added. “I signed a pledge to support the Republican nominee, and I will honour that pledge.”
Speaking to voters in New Hampshire, Mr Trump said his campaign had “got some word that one of our opponents, a very capable person, is dropping out”.
“In doing so, [Mr DeSantis] endorsed us,” the former president added, to loud cheers in the room.
He went on to say that he believed “most of” Mr DeSantis’ votes, “or certainly many of them”, would go to his campaign – but added “we don’t need them”.
At the event, Lynne Mason, 60, told the BBC that she thought Mr DeSantis’ “campaign was a little weak” and she had “expected more from him”.
Mr Trump, she added, “is the only person at this time who can save this country”.
After Mr DeSantis’ announcement, Trump’s campaign called “for all Republicans to rally behind President Trump” and slammed Ms Haley as “the candidate of the globalists and Democrats who will do everything to stop the America First movement”.
Mr DeSantis also took a swipe at Ms Haley, calling her a member of “the old Republican guard of yesteryear – a repackaged form of warmed-over corporatism”.
Ms Haley, a former US ambassador to the UN, responded by insisting she is the conservative – the “only one” – who can beat current US President Joe Biden.
“There’s two people in this race,” she told CNN in New Hampshire, referring to herself and Mr Trump. “That’s what we wanted all along, and we’re going to keep going.”
Mr DeSantis narrowly finished ahead of Ms Haley in last week’s Iowa caucus with 21% of the vote, compared to her 19%. Mr Trump received 51% of the vote.
At the time, Mr DeSantis framed the second-place finish as a victory, claiming that his campaign “got our ticket punched out of Iowa”. He contended that meant half of the voters in Iowa wanted to support someone other than the former president.
The Florida governor had spent the bulk of his time and resources in recent months campaigning in all 99 of the state’s counties and courting its conservative evangelical voters, however, which made it difficult to sell his loss to Mr Trump as a win.
His departure from the race allows Mr DeSantis to avoid a potentially further embarrassing third-place finish in New Hampshire to Ms Haley, who has focused far more of her resources in the state.
But a person familiar with Mr DeSantis’ election night plans in New Hampshire was completely caught off guard by the news of his exit.
The source told the BBC the campaign had just confirmed plans with them on Saturday for their election night celebration this coming Tuesday.
There were some early indications that this news might be on the horizon – Mr DeSantis had dropped out of several planned media appearances on Sunday, and had a single event scheduled in New Hampshire.
Chris Ager, the state committee chair of New Hampshire’s Republican Party, told the BBC that “the race has been moving toward a one-vs-one between Trump and Haley for a while”.
“This makes it so,” he added.