Donald Trump has suggested he may run for president again in 2024 - amid an angry attack on Joe Biden in his first major address since leaving the White House.

The Republican used his speech at the Conservative Political Action Conference (CPAC) in an apparent effort to cement his status as the party's undisputed leader despite his defeat in November.

"I stand before you today to declare that the incredible journey we began together... there's never been a journey so successful - we began it together four years ago and it is far from over," he said.

He dismissed suggestions he may start a new party, saying "we're not interested in them".

"We all knew the Biden administration was going to be bad, but none of us even imagined just how bad they would be," he said.

"He talked about energy. I thought 'this guy, actually, he's ok with energy'. He wasn't ok with energy... he wants windmills."