EXCLUSIVE – Republican presidential candidate Nikki Haley argues that Florida Gov. Ron DeSantis is "an echo" for former President Donald Trump and that DeSantis, who's expected in hours to join Haley and Trump in the race for the 2024 GOP presidential nomination, "needs to get out there and say what he believes."

Haley, the former two-term South Carolina governor who later served as ambassador to the United Nations during the Trump administration, took aim at DeSantis in a national exclusive interview with Fox News Digital on Wednesday in New Hampshire, the state that holds the first primary and second overall contest in the Republican presidential nominating calendar. 

DeSantis will declare that he's a candidate for president on Wednesday at 6 p.m. ET during a conversation with Elon Musk on Twitter, sources in the popular conservative governor’s political orbit confirmed to Fox News on Tuesday. Along with his announcement, DeSantis is expected to file paperwork with the Federal Election Commission, which officially launches his GOP presidential campaign. And his first national TV interview following the announcement will be with Fox News' Trey Gowdy Wednesday at 8 p.m. ET on "Fox News Tonight."

Haley in February become the first major Republican to challenge Trump, who remains the clear front-runner in GOP primary polls as he makes his third straight White House run. Even though he’s been on the 2024 sidelines until now, DeSantis is second in the surveys – although his standing has slipped in recent months – ahead of Haley and the rest of the actual and potential Republican White House contenders.

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She charged that DeSantis is "copying Trump. He needs to be his own person. He needs to get out there and say what he believes. What he thinks. If he’s going to be an echo for Trump, people will just vote for Trump. Why doesn’t he go out there. I’m my own person. You’re going to see – what you see is what you get. I’m going to tell you what I think. I’m going to tell you what I believe. And I’m going to let the chips fall where they may. He should do the same thing."

Asked by Fox News if her criticism of DeSantis will only benefit Trump and will be a replay of attacks between the GOP presidential candidates in the 2016 cycle that helped Trump win the nomination and eventually the White House, Haley answered, "It’s a primary. In a primary you show differences between people."

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"I am staking myself out. I am showing people why I’m different, what I can do, the fact that I was a two-term governor that took a double-digit unemployment state and turned it into an economic powerhouse. The fact that I was at the U.N., and I didn’t deal with one country, I dealt with 193. I had national security experience. I bring that to the table, and I talk about that."

Pointing to DeSantis, Haley argued, "He should talk about what he brings to the table. Our goal is to show who we are and why we’re different. I think he’s showing who he is and the fact that he’s just an echo of Trump. I think that’s not what the American people want to see."

Haley’s comments to Fox News come a day after her campaign released a memo that cast DeSantis as a lesser alternative to Trump and criticized the Florida governor for appearing to "mimic" the former president. Haley’s campaign hammered home that theme again early on Wednesday morning with a video titled "A choice, not an echo," which spotlights DeSantis’ past imitations of Trump and paints Haley as the former president’s true alternative in the GOP presidential field

DeSantis, who at age 44 is more than three decades younger than Trump, won his first election as governor in 2018 thanks to a major assist from the then-president. But he became a force of his own as he’s built a political brand that stretches from coast to coast.

The governor saw his popularity soar among conservatives across the country the past three years, courtesy of his forceful pushback against coronavirus pandemic restrictions and his aggressive actions as a culture warrior going after media, corporations and school unions. DeSantis, who cruised to an historic 19-point win in Florida, a onetime battleground state, racked up a slew of conservative policy victories – including a controversial six-week abortion law, tougher immigration laws, restrictions on gender and diversity instruction in schools, and green-lighting the ability to carry a concealed weapon without a permit – during Florida's just-concluded legislative session, courtesy of a GOP super majority in Tallahassee.

Trump, viewing DeSantis as this top 2024 GOP nomination threat, started targeting the Florida governor last autumn, nicknaming him "Ron DeSanctimonious." And those attacks from Trump and his allies have intensified in recent months.

Haley also took aim at Trump on Wednesday without naming him. As she headlined the latest edition of the "Politics and Eggs" speaking series at Saint Anselm College’s New Hampshire Institute of Politics ahead of her interview with Fox News, Haley emphasized, "We have got to have a new generational leader. We’ve got to leave the baggage. We’ve got to leave the negativity."

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Her comments appeared to be a jab at Trump, who has continued to relitigate his 2020 election loss to President Biden as he repeats his unproven claims that his defeat was due to an election "stolen" through "massive voter fraud." Additionally, the former president’s listing of his many legal grievances has also become a campaign staple this year.

Haley arrived in New Hampshire on Tuesday, the day after Republican Sen. Tim Scott of South Carolina formally launched his presidential campaign at a jam-packed event in his hometown of North Charleston. Haley, who as governor elevated Scott over a decade ago from the House to the Senate to fill a vacant Senate seat, shares many of the same friends, allies, donors and supporters. 

Asked if Scott’s entry into the race complicates her path to the nomination, Haley quickly answered that it "doesn’t complicate things. I welcome him to the party."