NEW YORK (AFP) - New York's star-studded Met Gala will focus on youth and diversity this year, with four co-chairs under the age of 30 - actor Timothee Chalamet, poet Amanda Gorman, singer Billie Eilish and tennis player Naomi Osaka.

Normally held in early May, the charity ball was postponed to Sept 13 in the hope that many Covid-19 restrictions will be lifted by then. The 2020 edition was cancelled due to the pandemic.

The honorary co-chairs will be Ms Anna Wintour, the editor-in-chief of Vogue who has turned the gala into a global event, designer Tom Ford and Mr Adam Mosseri, director of Instagram, sponsor of the event.

The Metropolitan Museum of Art's Costume Institute relies on the Met Gala to fund its work including exhibitions and acquisitions, and the cancellation of last year's event badly damaged its finances.

A regular on red carpets, Franco-American Chalamet, 25, has a reputation for fashionable outfits, wearing Alexander McQueen flower-printed suits, and - at the 2019 Golden Globes - a glittering Louis Vuitton harness.

Gorman, 23, became an international sensation after reciting her poem The Hill We Climb, inspired by the Jan 6 attack on the United States Capitol, at President Joe Biden's inauguration.

Gorman, who is African-American, then became the first-ever poet to perform at the Super Bowl, America's most-watched broadcast of the year.

Better known for her casual style, including large T-shirts, Eilish, 19, recently appeared in British Vogue in tight-fitting lingerie.

"Showing your body and showing your skin - or not - should not take any respect away from you," she told the magazine.

Osaka, 23, the world number two tennis player, has also made waves in the fashion world, becoming a Louis Vuitton ambassador.

Osaka, who has a Japanese mother and Haitian father, has also collaborated on designs for bags and swimsuits.

The Met Gala will be held in two stages, with a first reception on Sept 13 and another on May 2, 2022.