Ava DuVernay has criticised author Stephen King for posting "backward and ignorant" tweets about the lack of diversity at the 2020 Oscars.

The 2020 Academy Award nominations were announced on Monday, revealing that the vast majority of nominees were white males, with only one out of the 20 acting nominees being a person of colour.

The lack of diversity sparked a debate on social media, and The Shining author Stephen King, who has had many books adapted into films and TV shows, decided to weigh in on the issue and tell his followers he doesn't consider diversity when casting his vote in three Oscars categories.

"As a writer, I am allowed to nominate in just three categories: Best Picture, Best Adapted Screenplay, and Best Original Screenplay. For me, the diversity issue - as it applies to individual actors and directors, anyway - did not come up," he tweeted on Tuesday. "That said... I would never consider diversity in matters of art. Only quality. It seems to me that to do otherwise would be wrong."

His tweets sparked backlash online from many social media users, including Selma filmmaker DuVernay, who expressed her dismay at his remarks.

"When you wake up, meditate, stretch, reach for your phone to check on the world and see a tweet from someone you admire that is so backward and ignorant you want to go back to bed," she commented alongside a retweet of King's message.

Writer Roxane Gay also tweeted, "As a fan, this is painful to read from you. It implies that diversity and quality cannot be synonymous. They are not separate things. Quality is everywhere but most industries only believe in quality from one demographic. And now, here you are."

King returned to Twitter later to try and calm the backlash by writing, "The most important thing we can do as artists and creative people is make sure everyone has the same fair shot, regardless of sex, colour, or orientation. Right now, such people are badly under-represented, and not only in the arts... You can't win awards if you're shut out of the game."

The 2020 Oscars will take place in Los Angeles on 9 February.