Washington, July 27 : US President Joe Biden on Wednesday told Americans in an Oval Office address that he ended his re-election campaign to "unify my party” with the larger goal of protecting American democracy and that goal is larger than "personal ambition".

He found it a good time to "pass the torch to a new generation".

Biden, who had just recovered from Covid-19 infection and returned to the White House from self-isolation in his Delaware home on Tuesday, started haltingly but he settled down to his natural tone and tenor midway and went on to lay out his reasons for stepping aside and forging the path for his party and the country to protect and continue the democratic system handed down by the founders.

He spoke for nearly 11 minutes from behind the Resolute Desk in the Oval Office, wearing a blue tie, the colour used by Democrats to assert party affiliation.

"In recent weeks it's become clear to me that I need to unite my party in this critical endeavour," Biden said, of protecting American democracy.

"I believe my record as President, my leadership of the world, my vision of America's future, all merited a second term but nothing, nothing can come in the way of saving our democracy, that includes personal ambition."

Biden, 81, announced his exit from the 2024 race for the White House past Sunday under mounting pressure from his party to make way for a different candidate after a disastrous performance in the first presidential debate against his Republican rival, former President Donald Trump.

He had said then he would explain his reasons in an address later, which took place Wednesday in a widely anticipated prime time address.