Actor George Clooney has hailed a “selfless” US President Joe Biden for quitting the presidential election contest.

Clooney hit the red carpet at the Venice Film Festival on Sunday with friend Brad Pitt for the world premiere of Wolfs.

Ahead of that the Hollywood stars reflected on reuniting, the rise of streaming and Clooney’s New York Times op-ed in July in which he urged Biden to end his re-election bid.

Clooney’s article – in which he wrote the Biden of 2024 “was not the Joe ‘big f-ing deal’ Biden of 2010… [or] even the Joe Biden of 2020” – has been seen as one of the key developments in convincing the 81-year-old President to step out of the race against Republican contender Donald Trump.

Asked about the impact, Clooney said he’d not yet had to answer that question.

“The person who should be applauded is the President, who did the most selfless thing anyone’s done since George Washington,” Clooney said on Sunday (local time).

“All the machinations that got us there, none of that’s going to be remembered. And it shouldn’t be. What should be remembered is the selfless act.

“It’s very hard to let go of power. We know that. We’ve seen that all around the world. For someone to say, I think there’s a better way forward? All credit goes to him.”

Most of Sunday’s discussion, however, focused on Pitt and Clooney’s new film, an old-school action thriller directed by Jon Watts.

The two friends play lone wolf fixers unhappy to have been hired for the same job to cover up a bloody mess involving a district attorney.

It is the first time Pitt and Clooney have co-starred in a film since the Coen Brothers’ political satire Burn After Reading in 2008.

They are reported to have been paid $US35 million ($52 million) each for Wolfs – although Clooney denied that.

The movie will have a limited theatrical release on September 20, before hitting Apple TV+ on September 27.

Apple TV+ acquired Wolfs in a competitive bidding war, beating traditional studios and rival streaming services.

Deadline reported in 2021 that it was expected to come with a robust theatrical release, something the stars may have also forfeited money to ensure, it said.

Several weeks ago, Apple TV+ announced different plans: Theatrical would be limited. Streaming would be quick.

Clooney confirmed that he and Pitt did forfeit some of their salaries to guarantee a theatrical release – although “it is millions and millions and millions of dollars less than what was reported”.

He said it was a “bummer” that Wolfs‘ release wouldn’t be wider than a few hundred theatres.

Pitt added: “I think we’ll always be romantic about the theatrical experience but at the same time I love the existence of streamers … it’s a delicate balance. It’ll right itself.”

-with AAP