The announcement, delivered in a video, marks an about-face for the former Trump official, who said two years ago that she would not challenge her former boss for the White House in 2024.

But she changed her mind in recent months, citing, among other things, the country’s economic troubles and the need for “generational change”, a nod to the 76-year-old Trump’s age.

Haley, 51, is the first in a long line of Republicans who are expected to launch 2024 campaigns in the coming months.

Among them are Florida governor Ron DeSantis, former vice president Mike Pence, former secretary of state Mike Pompeo and senator Tim Scott of South Carolina.

President Joe Biden has said he intends to seek re-election in 2024, stalling any jostling for the Democratic nomination.

Haley has regularly boasted about her track record of defying political expectations, saying: “I’ve never lost an election, and I’m not going to start now.”

If elected, she would be the nation’s first female president and the first US president of Indian descent.

In a statement, Taylor Budowich, spokesman for Trump’s super PAC, said Haley was “just another career politician”.

“She started out as a Never Trumper before resigning to serve in the Trump admin,” he said.

“She then resigned early to go rake in money on corporate boards. Now, she’s telling us she represents a ‘new generation’. Sure just looks like more of the same, a career politician whose only fulfilled commitment is to herself.”