James Cameron was concerned that 'Avatar: The Way of Water' wouldn't be relevant over a decade after the original film was released.

The 68-year-old director has helmed the long-awaited sequel to his 2009 sci-fi epic 'Avatar', which is set to be released in December, but was worried that fans may have lost interest in the franchise in the intervening years – even though the original became the highest-grossing movie of all time.

James told The New York Times newspaper: "I was a little concerned that I had stretched the tether too far, in our fast-paced, modern world, with 'Avatar 2' coming in 12 years later.

"Right until we dropped the teaser trailer, and we got 148 million views in 24 hours. There's that scarce seen but wondered at principle, which is, 'Wow, we haven't seen that in a long time, but I remember how cool it was back then.' Does that play in our favour? I don't know. I guess we're going to find out."

The 'Titanic' director did admit that he would never have made the 'Avatar' sequel straight away, citing the success he had with the follow-ups 'Aliens' and 'Terminator 2: Judgment Day – both of which were released several years after the original films.

Cameron explained: "I think I could have made a sequel two years later and have it bomb because people didn't relate to the characters or the direction of the film.

"My personal experience goes like this: I made a sequel called 'Aliens', seven years after the first movie. It was very well received. I made a sequel called 'Terminator 2', seven years after the first movie. It did an order of magnitude of more, in revenue, than the first film."