The first sequel to the 2009 blockbuster sci-fi film is set to hit theaters in December 2016, with Josh Friedman, Rick Jaffa, Amanda Silver and Shane Salerno previously announced as collaborators with Cameron on the script.

"The biggest pressure I feel right now is cutting out things I love to get the film down to a length that is affordable," Cameron wrote on Saturday. "There hasn't been a problem finding new and wonderful things to include in the movie."

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Sam Worthington, Zoe Saldana and Stephen Lang, who portrayed the villainous Marine Colonel Quaritch, will reprise their roles in the sequel.

Cameron's Reddit AMA reply was in response to a query about whether Arnold Schwarzenegger would appear in the films. The director appeared to shoot down that rumor: "I don't see a role as the scripts are coming together that would be appropriate for him, so I would say probably not."

The helmer also reiterated that a planned adaptation of Battle Angel is "on hold" until after the three Avatar films were complete. Asked what he sees for the future of film, Cameron noted that he'd like to see less emphasis on mere spectacle.

"In terms of storytelling, I'd like to see Hollywood embrace the caliber of writing in feature films that we're currently seeing in the series on television -- more emphasis on character, and less on explosions and pyrotechnics," he wrote. "And I'm talking the big tentpole movies, I think they're obnoxiously loud and fast."