Thirteen months after she launched her 2024 Republican presidential campaign in Charleston, South Carolina, Nikki Haley is ending her White House bid, two sources confirmed to Fox News Digital.

The former two-term South Carolina governor who later served as U.N. ambassador in former President Donald Trump's administration is expected to say Wednesday morning that she is suspending her campaign for the GOP nomination, but she is not immediately expected to endorse Trump.

Haley is scheduled to speak Wednesday from Charleston at 10 a.m. ET.

In a Republican presidential field that topped a dozen candidates last summer, Haley was the final remaining rival to Trump, who for months has been the commanding frontrunner in the GOP race as he makes his third straight White House bid.

Haley – who in 2021 and 2022 made numerous trips to Iowa and New Hampshire, the two lead-off states in the Republican presidential nominating calendar – formally launched her 2024 campaign in February of last year. 

Haley polled in the single digits for much of last year and faced an uphill climb to win the nomination. But courtesy of well-regarded performances in the late summer and autumn in the first three GOP primary debates, Haley grabbed momentum and saw her poll numbers soar.

That surge increased in December, as Haley caught up with Florida Gov. Ron DeSantis in the latest Iowa polls and in national surveys, for a distant second place behind Trump.

And Haley zoomed to second place and narrowed the gap with Trump in New Hampshire, thanks in part to a crucial endorsement from Republican Gov. Chris Sununu.

Trump ended up winning the Jan. 15 Iowa caucuses by 30 points over DeSantis, with Haley finishing slightly behind the Florida governor in third place.

DeSantis, who was a distant third and mired in the single digits in the public opinion polls in New Hampshire, dropped out of the race two days before the primary, turning the GOP nomination battle into a two-candidate race between Haley and Trump.

Haley, thanks to strong support from independents, won 43% of the vote in New Hampshire, finishing 11 points behind Trump.

After Trump scored landslides in the Nevada and U.S. Virgin Islands GOP caucuses in early February, the race moved to Haley's home state of South Carolina.

While Haley campaigned relentlessly in her home state and Trump made only a handful of stops, the former president enjoyed the backing of South Carolina's governor, both senators, and scores of state lawmakers and officials. 

But Haley remained defiant amid increasing calls by fellow Republicans for her to drop out of the race.

"I refuse to quit. South Carolina will vote on Saturday. But on Sunday, I’ll still be running for president. I’m not going anywhere," Haley emphasized in a major speech a couple of days ahead of her home state primary.

And she emphasized that "I have no fear of Trump’s retribution."

On the campaign trail days ahead of the South Carolina primary, Haley told her supporters, "I will take the bruises. I will take the cuts. This is going to be messy and I'll take the hurt, because I believe nothing good comes easy. Sometimes we have to feel pain to appreciate the blessing."

Haley has also turned up the volume in her verbal attacks on Trump, from his legal entanglements to his controversial comments on NATO and the death of Russian opposition leader Alexei Navalny, as well as his mocking of her husband, who is overseas on a military tour of duty.

And she continued to spotlight both the 77-year-old Trump and 81-year-old President's Biden's verbal miscues as she repeatedly questioned their mental and physical durability and argued that it was time for a new generation to steer the country.

Trump ended up topping Haley by 20 points in South Carolina, and he followed that up with an even bigger win three days later in Michigan's Republican presidential primary.

But Haley kept going, as she campaigned across the country in the 15 states from coast to coast that held Super Tuesday GOP nominating contests on March 5.

Trump rolled into Super Tuesday with plenty of momentum, after sweeping the Michigan's GOP's party convention, and winning large victories in the Missouri, Idaho, and North Dakota caucuses.

"We’ve been launching like a rocket to the Republican nomination," Trump touted Saturday night at a rally in Richmond, Virginia, as he pointed to his ballot box victories in Michigan, Missouri and Idaho.

But Haley, who repeatedly highlighted that she would remain in the GOP nomination race at least through Super Tuesday despite the extremely long odds she faces, on Sunday enjoyed victory for the first time in the 2024 race.

Haley topped Trump by roughly 30 points in Washington D.C.'s Republican primary this past weekend. She captured 19 delegates and made history as the first woman to win a GOP presidential primary or caucus.

Haley, who garnered strong support in the GOP primaries from independents and whose fundraising remained formidable, said she was staying in the race as an option for voters dissatisfied with a likely Biden-Trump rematch. 

But Haley held no public events or election night gatherings on Super Tuesday evening and remained mum on any plans going forward.

Haley reiterated in an interview on Saturday with Fox News' Bill Melugin that "we're going to go as long as we're competitive," but she did not specifically define what competitive means.