Director James Cameron has revealed that the scripts for three Avatar sequels will be finished in the next six weeks. 

Speaking about the follow-ups to the 2009 hit movie, Cameron admitted there is huge pressure mounting as the writing process near its end.

He told Reddit: "The second, third and fourth films all go into production simultaneously. They're essentially all in preproduction now, because we are designing creatures, settings and characters that span all three films. 

"And we should be finished with all three scripts within the next, I would say, six weeks... There's always pressure, whether it's a new film or whether it's a sequel, to entertain and amaze an audience. 

"I've felt that pressure my entire career, so there's nothing new there. The biggest pressure I feel right now is cutting out things I love to get the film down to a length that is affordable.

"There hasn't been a problem finding new and wonderful things to include in the movie," he teased.

The first 3D Avatar sequel is expected to be released in cinemas by Christmas 2016, with the subsequent movies set for 2017 and late 2018 respectively.

Sam Worthington and Zoe Saldana will return for the three sequels.