In March 9, 2020 photo, US-Chinese actress Yifei Liu attends the world premiere of Disney's "Mulan" at the Dolby Theatre in Hollywood. (FREDERIC J BROWN / AFP)

Walt Disney Co on Thursday postponed the debut of its movie Mulan indefinitely, dealing a new blow to theater operators that were counting on the live-action epic to help attract audiences during a pandemic.

The Avatar sequel is now set to debut in theaters in December 2022, and the next Star Wars movie in December 2023

Mulan was scheduled to reach theaters in March but its release has been postponed several times as many cinemas remain closed. The film had most recently been set to debut on Aug 21 and theater operators had hoped it would help spark a late-summer rebound for movie-going.

Disney also said it had delayed the next film installments from two of its biggest franchises, Avatar and Star Wars, by one year as the novel coronavirus has disrupted production.

ALSO READ: Blockbusters delayed again as Disney pushes Mulan to August

The Avatar sequel is now set to debut in theaters in December 2022, and the next Star Wars movie in December 2023.

This photo taken on Dec 20, 2019 shows a couple looking at a promotional installation for the latest Star Wars movie "The Rise of Skywalker" at a mall in Beijing. (NOEL CELIS / AFP)

“It’s become clear that nothing can be set in stone when it comes to how we release films during this global health crisis,” a Disney representative said. “Today that means pausing our release plans for Mulan as we assess how we can most effectively bring this film to audiences around the world.”

The Mulan delay follows Warner Bros decision to postpone the August release of Christopher Nolan thriller Tenet. The two films were seen as theaters’ best chance to salvage part of the lucrative summer season.

This image released by Warner Bros. Entertainment shows Elizabeth Debicki, left, and John David Washington in a scene from "Tenet." (MELINDA SUE GORDON / WARNER BROS ENTERTAINMENT VIA AP)

The AMC and Cineworld movie theater chains on Thursday pushed back the reopening date for their US theaters to at least mid-August from the end of July.

READ MORE: Disney delays 'Avatar 2,' sets dates for 3 'Star Wars' films

The Avatar delay also removes one of next year’s biggest movies.

The follow-up to James Cameron’s 2009 blockbuster that is the second highest-grossing film of all time, Avatar 2 had faced numerous delays even before the coronavirus outbreak. At one time it had been expected to reach theaters in 2014.

Disney has not released details on the next Star Wars film.