Los Angeles, Apr 4 (IANS): Actress Sigourney Weaver, who played the role of Grace Augustine in "Avatar", says the shooting for the epic science fiction films sequel will begin in autumn this year.

"We're starting. We're starting training, and we're starting -- hmm, I probably can't say anything. We will be actually shooting it by the fall," Weaver told hollywoodreporter.com.

Earlier, director James Cameron announced that the scripts of all four "Avatar" sequels are completed and that stars Sam Worthington and Zoe Saldana were set to return alongside Weaver.

However, he later said the second film won't be ready for a 2018 release date.

Weaver assures that audiences' patience will be rewarded in time.

"I'm telling you, these scripts are so amazing, I'm not worried about (disappointing fans) at all. Am I worried about how we're going to bring them to life? Yes, because they're so ambitious. They're so worth it. They're well worth waiting for. I'm not worried about that at all. We're trying to get it done as quickly as possible," she said.