Trump warns 2024 election 'our one shot' to save America

Donald Trump warned that the next election would be America's last chance for salvation as he attempted to revive a faltering third run for the White House in two US states that launched his winning 2016 presidential campaign.

Buffeted by political and legal headwinds, the 76-year-old Republican addressed a few hundred supporters at an intimate rally in South Carolina's capital Columbia.

"The 2024 election is our one shot to save our country and we need a leader who's ready to do that on day one," Trump said from a podium beneath the Statehouse rotunda, flanked by American flags and some of his most loyal political allies.

"There's only one president who has ever challenged the entire establishment in Washington, and with your vote next year, we will do it again," he said, seeking to revive his 2016 image as an insurgent outsider.

His most divisive remarks were reserved for the conservative critics he refers to as "RINOs" -- Republicans in name only -- whom he criticised at both events, arguing in New Hampshire that they were "even more dangerous than Democrats."

During his address to party activists in Salem he had touted his record on law and order, immigration and "rebuilding" the US military as he vowed to save the country from "being destroyed by a selfish, radical, corrupt political establishment."

"I'm more angry now and more committed now than I ever was," Trump said. "We need a president who's ready to hit the ground running on day one."