Florida Governor Ron DeSantis said on Wednesday he would seek the 2024 Republican nomination for president, setting up a showdown with his one-time ally, former President Donald Trump, that will shake up the race for the White House.

DeSantis made the announcement in a video ahead of an audio interview on Twitter with its CEO, Elon Musk.

"We need the courage to lead and the strength to win," DeSantis said. "I'm Ron DeSantis, and I'm running for president to lead our great American comeback."

With a rising national profile and what are expected to be deep financial resources, DeSantis, 44, immediately becomes Trump's biggest rival for the Republican nomination.

But polls show Trump with more than a 2-to-1 edge over the Florida governor, who has long been considered a Republican rising star and the herald of a new generation of leaders in the party. Trump, who announced in November, has also had a head start in organizing his campaign in key early voting states.

Supporters and donors will be keenly watching to see if DeSantis now takes the fight to Trump, who has been relentlessly attacking him with little reaction, much to the frustration of some DeSantis allies who wanted him to respond more forcefully.

Musk, the CEO of Tesla and Twitter with 140 million Twitter followers, said earlier that his presence at Wednesday's event would not constitute an endorsement but would reflect his desire to make the service more of a town square.

DeSantis on Wednesday was also expected to convene a meeting of his top donors at a Miami hotel, where they will immediately launch his fundraising efforts.

Other declared Republican candidates include Nikki Haley, former US ambassador to the United Nations, and Tim Scott, a US senator from South Carolina. (Reuters)