The 64-year-old actress portrayed Dr. Grace Augustine, an exobiologist and head of the Avatar program, in the original film. She is shot toward the end of the movie, and dies despite Na'vi efforts to revive her. Director James Cameron already has Avatar 2, 3 and 4 planned, and revealed Monday that Weaver will return for the sequels.
"Sigourney and I have a long creative history, dating back to 1985 when we made Aliens," he begins. "We're good friends who've always worked well together, so it just feels right that she's coming back for the Avatar sequels."
"Her character of Grace Augustine, as fans know, died in the first movie," he continues. "So she's playing a different and in many ways more challenging character in the upcoming films. We're both looking forward to this new creative challenge, the latest chapter in our long and continuing collaboration."
Avatar 2 is scheduled for release in December 2016. Sam Worthington and Zoe Saldana will reprise their roles as Jake Sully and Neytiri. It was previously confirmed that Stephen Lang will return as villain Miles Quaritch, although he also appeared to die in the first movie.