"Avatar" director James Cameron said he still aims to make four sequels to the 2009 science-fiction blockbuster, likening the series to "The Godfather".

Cameron also said he hoped "Avenger fatigue" would set in after the next instalment of the superhero franchise, saying there are "other stories to tell".

Speaking to reporters on Saturday, Cameron said he was about 100 days into filming the second and third "Avatar" installments under a deal with Fox. If those are successful, he plans to continue with the fourth and fifth movies, which he already has written.

"I'm personally committed to all of them," he said at the Manhattan Beach, California, studio where the sequels are being made.

Designs for creatures and characters for the four planned sequels are posted on walls inside the studio, Cameron said, but he did not show them to reporters.

"If you were Rupert Murdoch, you could go see them," he joked, adding: "Or Bob Iger."