The first of three sequels to the widely successful 2009 film "Avatar" will be pushed back to 2017, director James Cameron announced, according to Hollywood Reporter.

The director attributed the delay to the complexity of writing the much-awaited three sequels, the first of which was originally slated for a 2016 release.

"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 in Wellington, New Zealand, where he was taking part in the promotion of the local film industry there along with other directors.

Additionally, all three sequels will be filmed at once and will be released over three consecutive years.

"We're writing three simultaneously. And we've done that so that everything tracks throughout the three films. We're not just going to do one and then make up another one and another one after that," said the director, who won three Oscars for his work on the film.

"And parallel with that, we're doing all the design. So we've designed all the creatures and the environments," Cameron continued.

Cameron, 60, noted the importance of building seamless links between the sequels while still giving each one a resolution. The scripts for the three upcoming movies will be finished by the end of January, he said.

The movies' producer Jon Landau, meanwhile, has said that the production team is being extra careful in light of the Sony hack.

"I will only say yes but will not tell you how," he said in jest.

"Avatar" earned $2.8 billion after it was released in 2009, making it the highest-grossing film of all time. It won Academy Awards for cinematography, visual effects and art direction and best drama at the Golden Globes, according to ABC News.

The film was shot in New Zealand, and Cameron is planning to shoot all three sequels there.