Los Angeles: Director James Cameron has broken his silence over the time lag between the two parts of the sci-fi film series Avatar, by saying that big-budget and visionary movies usually take time to come together.

The 62-year-old director cited the example of the Terminator and Alien franchise to drive his point home, reported CNN.

"It was a seven-year gap between The Terminator and Terminator 2: Judgment Day, a seven-year gap between Alien and Aliens. It's going to be obviously more like a ten-year gap between Avatar and Avatar 2.

"But Avatar 2 you are going to with not the promise, but the certainty of three more films beyond that, and that's a very different concept with the audience. And a lot of the delay has been around creating that overall vision," said Cameron.

Recently, the four sequels were given release dates by 20th Century Fox, starting December 18, 2020, the rest coming December 17, 2021, December 20, 2024 and December 19, 2025.

The first installment in the series released on December 18, 2009.