Hollywood actor George Clooney, one of the Democratic Party's top fundraisers, on Wednesday called on US President Joe Biden to urge him to end his unsuccessful re-election campaign.

Clooney, a member of Hollywood's elite who has been a key supporter of Democrats, joined a growing list of public figures calling for the 81-year-old Biden to step down after his poor debate performance against Donald Trump last month.

"I love Joe Biden," Clooney wrote in an op-ed for The New York Times. - I consider him a friend and believe in him ... But the one battle he can't win is the fight against time."

"That's not just my opinion, it's the opinion of every senator, member of Congress and governor I've spoken to privately," Clooney wrote. - It's all about age. Nothing more than that. But nothing that can be reversed, either."

Clooney's appeal was quickly echoed by Hollywood director Rob Reiner, an ardent Democrat who a few days ago also demanded that Biden resign.

"My friend George Clooney made clear what many of us have been saying ... Democracy faces an existential threat. We need someone younger to fight back. Joe Biden needs to step aside," Reiner wrote on his microblogging site X. 

Clooney, 63, who calls himself a "lifelong Democrat," co-hosted a star-studded fundraiser with Biden in Los Angeles last month, which was also attended by former President Barack Obama. Biden's campaign said the event raised a record $28 million.