Cameron: Jackson had it easy with Lord of the Rings

James Cameron is "deep into" the 'Avatar' sequels, and thinks 'Lord of the Rings' filmmaker had it much easier when making his movies.

The acclaimed filmmaker is enjoying penning the scripts for the second and third installments in his sci-fi franchise and says his work is quickly gaining momentum.

He said: "I'm deep into it and I'm living in Pandora right now. There is that start up torque where you feel it's coming to you. Then you build up momentum. That's when it gets fun. The characters talk and it's writing itself. I'm almost there right now. It's building fast."

Development on 'Avatar' - which was released in 2009 - began in 1994 and Cameron admits he is reluctant to set release dates for the second and third movies.

He told PlayGoesStrong.com: "As for a release date that will be determined by when I get the script out. No pressure!"

Though the writer-and-director is enjoying his work, he admits to feeling envious of fellow filmmaker Peter Jackson, as his 'Lord of the Rings' trilogy was all based on existing books.

He said: "I was talking the other day with Peter Jackson and said, 'You had it easy dude. You had the books when you did the second and third Lord of the Rings. I have to create my own books in my head and extract a script from it.' "

'Avatar', which starred Sam Worthington and Sigourney Weaver, became the highest grossing film of all time upon its release, earning more than $2bn worldwide.