Cameron explains why 'Avatar' sequels took 13 years to make

The world premiere of Avatar: The Way of Water took place in London’s Leicester Square on Tuesday, with the film’s stars coming together to celebrate the premiere. Stars included Kate Winslet, James Cameron, Sam Worthington, Sigourney Weaver and Andy Serkis. DEADLINE caught up with them.

Winslet told the interview that it was great to be back working under Cameron's direction after 25 years and said he was absolutely "amazing".

“He’s really good at bringing actors together and letting them figure things out,” she said at the premiere. “If something isn’t working, he’ll say, ‘Well, let’s do something else.’ So there was a really great sense of collaboration, and actually, I think it was probably better than I expected.”

Winslet added that "everyone was very open and fluid" during the filming. It's been 25 years since "Titanic" was released in theaters, and Winslet reflected on her experiences from then to now, saying that Cameron is "much more peaceful and calm" now that he is a parent.

Cameron finally explained why it took 13 years to film the sequel to "Avatar".

"First, I did a couple of years of deep sea adventures. Then we got serious about Avatar, and we wrote four scripts - it took a couple of years," he said. "What we're trying to do is kind of prepare the whole series in advance so we can put them out there a couple of years apart so that once we come back, we're well established."

"Avatar 2: The Path of Water" will be officially released in theaters in China on December 16, and ticket pre-sales have now begun.