Nikki Haley ends U.S. presidential election campaign

Republican former UN ambassador Nikki Haley suspended her White House campaign, declining to endorse former president Donald Trump but calling on him to earn the support of moderates and independents who backed her in the primary.

"It is now up to Donald Trump to earn the votes of those in our party and beyond who did not support him, and I hope he does that," Haley said in a televised address in Charleston, South Carolina.

Haley was in a two-person contest with Trump for the chance to face President Joe Biden in November's election but won just one state on "Super Tuesday" and never presented a serious obstacle in Trump's path to the nomination.

The 52-year-old was little known outside her native South Carolina before Trump tapped her as ambassador to the United Nations back in 2017 and used the high-profile UN post to cultivate an image as a plain-speaking conservative.

She prided herself on being the last challenger standing between the "chaos" of Trump and the 2024 Republican White House nomination.

"I am filled with gratitude for the outpouring of support we've received from all across our great country," Haley added.

"But the time has now come to suspend my campaign. I said I wanted Americans to have their voices heard -- I have done that. I have no regrets."

Trump reiterated his willingness to debate Biden. Debates are typically held after the parties' nominating conventions in July and August.

In response, Biden campaign spokesman Michael Tyler said, "That's a conversation we'll have at the appropriate time in this cycle."

Trump refused to participate in any of the debates held during the Republican nomination fight.

Haley lasted longer than any other Republican challenger to Trump but never posed a serious threat to the former president, whose iron grip on the party's base remains firm despite multiple criminal indictments.