US film director Francis Ford Coppola received a lengthy standing ovation after the world premiere of his sci-fi epic Megalopolis.

Ford Coppola hugged the film’s leading stars, Adam Driver, Nathalie Emmanuel, Aubrey Plaza and Giancarlo Esposito, and threw his straw hat into the crowd after the first official screening at the 77th Cannes Film Festival.

The film marks a decades-long passion project for The Godfather director, who is said to have had the idea for the story more than four decades ago.

77th Cannes Film Festival
DB Sweeney, Grace VanderWaal, Giancarlo Esposito, Aubrey Plaza, Francis Ford Coppola, Romy Croquet Mars, Adam Driver and Nathalie Emmanuel at the Megalopolis premiere (Doug Peters/PA)

After the film debut, Ford Coppola reportedly received a seven-minute standing ovation, telling the audience “it is impossible to find words to tell you how I feel”, in a video from US outlet Deadline.

Ford Coppola, whose wife Eleanor died last month, introduced members of his family to the crowd, before describing the film stars and crew as “all my family”.

“That is who we should pledge our allegiance to, our entire family and the beautiful home earth that we have, that is my wish, that the children should inherit a beautiful world from us.

“The most beautiful word I think in any language is speranza,  hope (in Italian).”

US actor Richard Gere was among the stars celebrating Ford Coppola at the end of the film.

77th Cannes Film Festival
Francis Ford Coppola at the Megalopolis premiere (Doug Peters/PA)

Gere, 74, who starred in Ford Coppola’s The Cotton Club in 1984, said of the film: “Totally crazy of course, the movie is crazy and only a crazy man could make that movie.”

Hollywood stars descended on the red carpet for the world premiere in Cannes.

In the film, Driver plays an architect who is in competition with the mayor of New York, as he wants to build the city into a utopia after a disaster.

Ford Coppola, who reportedly funded the big-budget film himself, is competing for a third prestigious Palme d’Or award at the French festival, having received his first for The Conversation and his second for Apocalypse Now.

British actress and Game Of Thrones star Emmanuel posed on the red carpet wearing a custom white Chanel Haute Couture gown, while co-star and Saturday Night Live comedian Chloe Fineman debuted a strapless red sparkly Celine number.

77th Cannes Film Festival
Nathalie Emmanuel on the Megalopolis red carpet (Doug Peters/PA)

The White Lotus star Plaza arrived on the red carpet wearing a custom long-sleeved cream Loewe gown with Casadei shoes, while Driver opted for a white dinner jacket and black bow tie.

The film features a large ensemble cast including Transformers star Shia LaBeouf, two-time Oscar winner Dustin Hoffman and Breaking Bad actor Giancarlo Esposito, as well as Jon Voight, Laurence Fishburne, Talia Shire, Kathryn Hunter and DB Sweeney.

Ford Coppola, 85, has won six Academy Awards.

He won his first Oscar in 1971 for writing epic biographical war film Patton about US General George S Patton during the Second World War, before picking up awards in the same category in 1973 and again two years later for The Godfather and its sequel.

He also won the gong for best director in 1975 for The Godfather II, about Vito Corleone, the head of a mafia family, which also won best picture in the same year.

In 2011, Ford Coppola was awarded the Irving G Thalberg Memorial Award.