Key Avatar stars Sam Worthington and Zoe Saldana have agreed to reprise their roles for all of the upcoming Avatar sequels currently in pre-production.

Fox has announced that Worthington will return as the wheelchair-bound Marine Jake Sully, and Saldana will play Neytiri, the Na’vi huntress. Avatar 2 is set for a December 2016 release, with the third and fourth films following in 2017 and 2018. Fox is hoping that the actors can start preparing their roles at the end of this year, with a view to starting filming in March 2015.

James Cameron will direct all three, writing the script for Avatar 2 with Josh Friedman; Avatar 3 with Rick Jaffar & Amanda Silver; and Avatar 4 with Shane Salerno.