Hollywood's two top leading men -- George Clooney and Brad Pitt -- promise to set the Venice Film Festival alight on Sunday with the premiere of their new film "Wolfs".

The action comedy, pitting one professional "lone wolf" fixer against another, is one of the highlights of the 10-day festival, where it is playing out of competition on the glamorous Lido.

Fans will be sure to await the arrival of the dashing movie stars by water taxi from Venice, with a world premiere scheduled for Sunday evening.

The 81st edition of the world's oldest film festival has been awash with stars this year, with Clooney and Pitt following on the red carpet Nicole Kidman, Cate Blanchett and Angelina Jolie -- Pitt's ex-wife.

Expected Monday will be Julianne Moore and Tilda Swinton, starring in a new film from Spain's Pedro Almodovar, while Lady Gaga and Joaquin Phoenix will dominate Wednesday's festivities with the premiere of the sequel to "Joker", "Joker: Folie a Deux".

In the Apple TV+ production from US director Jon Watts, Clooney and Pitt play professional "lone wolf" fixers forced to work together when both are called in to clean up after a high-profile crime.

More than colleagues, Clooney and Pitt are accomplices, with an easy rapport and self-deprecating humour that the Coen brothers tapped in 2008's "Burn After Reading", or on display in the trilogy of heist films "Ocean's Eleven" (2001-2007).

With "Wolfs", the characters "find their night spiraling out of control in ways that neither one of them expected", explains the production, which has already announced a sequel.

Watts comes to "Wolfs" after directing the "Spider-Man: Homecoming" trilogy starring Tom Holland and Zendaya.

The film will have only a limited theatrical release before going to streaming around the world on Apple TV+ September 27.

Sunday's offerings also include the premiere of "The Brutalist" from US director Brady Corbet, a three-and-a-half-hour film that sees Adrien Brody play a Hungarian Jewish architect embarking on a life-changing project. 

On Monday, Almodovar returns to the Lido with his first full-length film in English, "The Room Next Door", with Moore and Swinton, while Daniel Craig is the star of Tuesday's premiere of "Queer", an adaptation of the William Burroughs novel set in 1940s Mexico City.