Sigourney Weaver will return for the upcoming Avatar sequels, it has been revealed.

In James Cameron's original 2009 movie Weaver played Dr Grace Augustine, but her character was killed off at the end of the film.

However, the director has now confirmed that she will have a "more challenging" role in the three follow-up films.

Cameron said in a statement: "Sigourney and I have a long creative history, dating back to 1985 when we made Aliens.

"We're good friends who've always worked well together, so it just feels right that she's coming back for the Avatar sequels."

He added: "We're both looking forward to this new creative challenge, the latest chapter in our long and continuing collaboration."

Avatar stars Sam Worthington, Zoe Saldana and Stephen Lang will also be reprising their roles for the upcoming movies.

Avatar 2 will hit cinemas in December 2016.