Originally set for a 2016 release, James Cameron's science fiction film was beset by multiple delays due to plot issues and other needed alterations. Master Herald earlier reported that the award-winning director was having a hard time writing the film's script. Apparently, "Avatar" was initially planned for four sequels and was needed to be reduced into just a trilogy.

In an interview with Associated Press, Cameron said that the writing process was "very involved" and admitted that the film's initial release date was a tad "too ambitious."

"There's a layer of complexity in getting the story to work as a saga across three films that you don't get when you're making a stand-alone film," he said.

The third and fourth films are expected to come out on the same dates in 2018 and 2019, respectively. Cameron will team up with Josh Friedman (The Black Dahlia) for "Avatar 3" and Shane Salermo (Armageddon's) for the last movie.

"Avatar 2" will still follow Pandora native Neytiri and ex-marine James Sully, eight years after the events in the first film. Zoe Saldana and Sam Worthington will reprise their roles in all sequels. Filming is scheduled to start next year.

Producer Jon Landau said although the sequel is a bit delayed, it will not disappoint. He gave tantalizing hints on what fans should expect, disclosing that humans will play a larger role in "Avatar 2" and that there will be "good and bad ones."

The film is also expected to pay homage to James Horner, who worked with Cameron, composing and scoring music, since the "Titanic." Horner was already working in the pre-production stages of all "Avatar" sequels before his death earlier this month. He died in a California plane crash. 

In a joint statement Cameron and Landau reported by BBC, both expressed how "the Avatar community has lost one of our great creative lights."

"James' music was the air under the banshees' wings, the ancient song of the forest, and the heartbeat of Eywa. We have lost not only a great team-mate and collaborator, but a good friend," they said.

The much-awaited sequel to the 2009 box office movie, Avatar 2, will hit the cinemas Christmas 2017, according to 20th Century Fox.