Avatar creator James Cameron has promised fans that the long-awaited sequel will be worth the wait.

The original movie was released in 2009 and quickly became the highest-grossing film of all time - a record it held until the release of Avengers: Endgame last year.

Production on four sequels is now underway concurrently in New Zealand, with Sam Worthington, Zoe Saldana and Sigourney Weaver all reprising their roles from the first film.

"I deal with images in that world every single day and there are some days when I look at those images and say, 'This is really amazing'," Cameron told the Toronto Sun.

"I'm not patting myself on the back with the comment. It's a distillation of some of the best designers in the world and a great cast.

"But if you've got the script right and the design right and you have a great cast, then it's just an iterative process to get the whole thing shot and assembled."

Avatar 2 will be released in December 2022, with the remaining sequels following every two years thereafter.