UNITED STATES - JANUARY 11: Ranking member Sen. Tim Scott, R-S.C., speaks during the Senate Banking, Housing, and Urban Affairs Committee hearing titled "Stopping the Flow of Fentanyl: Public Awareness and Legislative Solutions," in Dirksen Building on Thursday, January 11, 2024. (Tom Williams/CQ-Roll Call, Inc via Getty Images)
CNN  — 

Former GOP presidential candidate and South Carolina Sen. Tim Scott endorsed Donald Trump on Friday in New Hampshire.

The endorsement is a blow of sorts to his fellow South Carolinian Nikki Haley, who appointed him to his Senate seat in 2012, and another sign of Trump’s commanding presence on top of the party.

“We need a president who will close our southern border today. We need Donald Trump,” Scott said while appearing on stage with the former president at a campaign event in Concord, New Hampshire.

“We need a president who will unite our country. We need Donald Trump,” he continued. “We need a president who will protect your Social Security and my mama’s Social Security. We need Donald Trump.”

While introducing Scott to the stage, Trump said the senator gave him his endorsement two days ago. The decision to wait to publicly roll it out emphasizes how significant the Trump campaign views his support, and its desire to play up his endorsement with as much fanfare as possible in the final days before the New Hampshire primary.

CNN previously reported that Trump had been in talks with Scott behind the scenes about winning his endorsement, according to multiple sources with knowledge of the talks.

Trump’s inner circle had originally hoped that Scott would endorse before the South Carolina primary, sources familiar with internal discussion told CNN. The timeline was accelerated, however, as Haley saw a spike in the polls in New Hampshire.

When asked about Scott’s plans during a visit to a New Hampshire diner on Friday, Haley replied, “We’ll wait and see if it happens.” She then ignored other questions on her way out.

Later Friday, she said in a statement, “Interesting that Trump’s lining up with all the Washington insiders when he claimed he wanted to drain the swamp. But the fellas are gonna do what the fellas are gonna do.”

The former South Carolina governor did not know that Scott was planning to go ahead with the endorsement, a source close to Haley said. Haley had called Scott in recent days to seek his endorsement in the 2024 race, a source familiar with the call confirmed to CNN.

People who know them both weren’t surprised by Scott’s decision to ultimately endorse the former president, but the timing of his endorsement — four days before the New Hampshire primary — was noted in both of their circles, given that Trump has been concerned about Haley’s standing in the state.

By announcing the endorsement ahead of the New Hampshire primary, Trump’s team aims to paint Haley as disliked by the people who would theoretically know her best in her home state.

Trump on Friday said Haley would “probably” not be his running mate should he win the Republican nomination as he viciously attacked her ahead of the primary in the state.

“She is not presidential timber. Now when I say that, that probably means that she’s not going to be chosen as the vice president,” Trump said at the campaign event.

South Carolina Reps. Russell Fry and William Timmons are also expected to campaign with the former president in New Hampshire this weekend, Fry told CNN, as Trump’s team launches a full court press against the former South Carolina governor.

This includes South Carolina Gov. Henry McMaster, who will campaign with Trump in Manchester, New Hampshire, on Saturday.

While Trump’s team has projected confidence that the former president will win the New Hampshire primary Tuesday, his advisers have admitted that they believe the margins are closer in New Hampshire than any other early voting state.

Scott launched his presidential campaign in May and made his personal story a central narrative, often speaking about growing up in poverty in South Carolina raised by a single mother.

But after several months of failing to gain traction, the senator suspended his bid in November. He told Fox News’ Trey Gowdy at the time that he would not back another Republican candidate, saying he believed “the best way for me to be helpful” was to withhold an endorsement in the primary. Scott also said he had no intention of accepting a vice presidential nomination, reaffirming a position he had repeated frequently on the campaign trail.

Throughout his campaign, Scott’s criticism of Trump was relatively tame compared with his attacks on other primary contenders. He often expressed support for policies enacted during the Trump administration, but regularly argued that Trump lacked the support in key swing states needed to carry Republicans to victory in a general election.

Prior to the 2024 campaign, Scott had long been friends and political allies with Haley. In 2012, Haley appointed Scott to the vacant seat left by Sen. Jim DeMint, saying Scott had “earned the seat” from his personality and record. Following Scott’s departure from the primary, several of Scott’s financial backers quickly pivoted to Haley.

This headline and story have been updated with additional developments.

CNN’s Kaitlan Collins, Manu Raju and Alayna Treene contributed to this report.