PROGRAMMING ALERT: Watch the Fox News Town Hall with former U.N. Ambassador Nikki Haley LIVE tonight at 6pm ET.

DES MOINES, IA. – With one week until Iowa’s caucuses kick off the Republican presidential nominating calendar, Nikki Haley is participate in a Fox News town hall as her numbers move in the right direction.

“Momentum is surging, Nikki’s message is resonating, and Americans are rallying behind our movement in droves,” the GOP White House candidate’s campaign wrote in an email to supporters on Monday.

And Haley, a former two-term South Carolina governor who later served as ambassador to the United Nations in former President Donald Trump’s administration, touted in a Fox News interview this past weekend that “we can feel the momentum on the ground. We can feel the excitement.”

Once a long-shot for the nomination, Haley has soared in recent months, thanks in part to her well-regarded performances in the first three Republican presidential primary debates.

GREAT EXPECTATIONS: THE PRESSURE’S ON FOR TRUMP, DESANTIS, AND HALEY TO PERFORM IN IOWA’S CAUCUSES

Haley over the past month has caught up with Florida Gov. Ron DeSantis in the latest Iowa polls and in national surveys, for a distant second place behind Trump, who remains the commanding front-runner for the nomination as he makes his third straight White House run.

And Haley has surged to second place and narrowed the gap with Trump in New Hampshire, which holds the first primary and votes second – just eight days after Iowa. Helping to boost Haley in New Hampshire, where independent voters play a crucial role in the state’s storied primary, is popular Gov. Chris Sununu, who backed her last month.

CHRISTIE TURNS UP THE VOLUME ON HALEY AS SHE CLOSES THE GAP WITH TRUMP

But with her rise in the polls comes more scrutiny for Haley, and more incoming fire from her rivals, as she takes questions Monday evening at a Fox News town hall in Des Moines from hosts “Special Report” chief political anchor Bret Baier and “The Story” executive editor and anchor Martha MacCallum. The hour-long town hall starts at 6pm ET and will be in front of a live audience.

Haley’s failure to mention slavery when answering a question late last month over the caucuses of the Civil War quickly went viral, and provided instant ammunition for her GOP presidential competitors. So did her comments this past weekend that you “change personalities” from Iowa to New Hampshire and last week that New Hampshire voters “correct” the results of the Iowa caucuses.

DeSantis, who is staking much of his campaign on a strong Iowa finish, charged Thursday in a local radio interview in the Hawkeye State that Haley was “incredibly disrespectful to Iowans to say somehow their votes need to be corrected.”

And another rival – former New Jersey Gov. Chris Christie, who is making his second White House run – accused Haley of acting “immature.”

Haley, during a CNN town hall last week in Iowa, said her comment was intended as a joke, noting “we’ve done 150 plus town halls. You got to have some fun, too.”

FIRST ON FOX: HALEY FUNDRAISING SOARS THE PAST THREE MONTHS

Christie and DeSantis have also taken aim at Haley for not being vocal enough in her criticism of Trump, and criticize her for not categorically saying she wouldn’t accept – if asked – to serve as the former president’s running-mate.

Meanwhile Trump, his campaign, and an aligned super PAC, have increasingly targeted Haley in recent weeks.

Longtime Iowa-based Republican consultant Jimmy Centers noted that Trump’s campaign and DeSantis – through his aligned super PAC – “have built organizational juggernauts.”

“Ambassador Haley has a message that is resonating, and she has built momentum. Now is the time for a campaign’s organization to shine,” Centers, who served as communications director for former Iowa Gov. Terry Branstad and current Gov. Kim Reynolds, emphasized.

While Haley has been criss-crossing Iowa, holding town halls and reaching out to voters, Monday’s town hall with Fox News will give her access to a wider audience, both in the Hawkeye State and across the nation.

DeSantis joins Fox News Tuesday for a similar town hall, with Trump taking questions from Baier and Macullum on Wednesday.

Get the latest updates from the 2024 campaign trail, exclusive interviews and more at our Fox News Digital election hub.