Former South Carolina Gov. Nikki Haley said on Tuesday that she will seek the Republican presidential nomination in 2024, putting her at odds with one-time boss Donald Trump, the ex-president also seeking to win back the White House.

"I'm Nikki Haley and I'm running for president," Haley said in a video that her team sent out by email.

Haley, a former South Carolina governor who served as Trump's U.S. ambassador to the United Nations, will lay out her campaign plans in a speech in Charleston, South Carolina, on Wednesday.

She became Trump's first direct challenger in a Republican field expected to grow in coming weeks and months.

Other high-profile Republicans looking at a 2024 run include Florida Gov. Ron DeSantis, former U.S. Vice President Mike Pence, U.S. Sen. Tim Scott of South Carolina, New Hampshire Gov. Chris Sununu and former Arkansas Gov. Asa Hutchinson, among others.

"It’s time for a new generation of leadership — to rediscover fiscal responsibility, secure our border, and strengthen our country, our pride and our purpose," Haley said in her video.

She also harked back to her foreign policy experience.

"China and Russia are on the march. They all think we can be bullied, kicked. You should know this about me: I don’t put up with bullies. And when you kick back, it hurts them more if you’re wearing heels," she said.