'Avatar' will "definitely" get a sequel.

The movie's lead actor Sam Worthington - who plays paraplegic marine Jake Sully in the action adventure film - confirms he and director James Cameron will return to make a second movie.

He said: "The deal was if we made a billion dollars we'd grab the manpower and undertake the job.

"Well, we've made about $2.6 billion at the moment so we're screwed, we're definitely going back."

However, he admits there is no timescale for the project yet.

Sam told BBC Newsbeat: "The boss, Jim Cameron, he's not just going to make it for the sake of it.

"He always wants the challenge, he always wants to push the envelope and raise the bar and I think audiences will demand that of 'Avatar 2' and when he finds the challenge that's when we go back to work."

Meanwhile, Cameron has confirmed the movie will be returning to cinemas following on from its DVD release.

He told MTV: "Well, here's what's in discussion and it's not locked in yet. After the DVD release of 'Avatar', we're going to do a theatrical re-release toward the end of the summer, into September. "Because there were a lot of people who still wanted to see the movie in IMAX 3-D that didn't get a chance to do it.

"We know people still want to have that theatrical experience. We actually think that the home experience and the theatrical experience can co-exist."