(James Cameron's "Avatar."20th Century Fox)

Director James Cameron has shed some light on the central plot of his upcoming four sequels to "Avatar," his 2009 blockbuster that grossed over 2.7 billion at the box office worldwide.

In an interview with Variety, Cameron explained that the four films will revolve around a "family saga" between the "Avatar" protagonists.

"The storyline in the sequels really follows Jake and Neytiri and their children," Cameron said. "It's more of a family saga about the struggle with the humans."

The current release schedule for the sequels is as follows: "Avatar 2" (Christmas 2018), "Avatar 3" (Christmas 2020), "Avatar 4" (Christmas 2022), and "Avatar 5" (Christmas 2023).

As Vulture points out, however, Cameron has repeatedly pushed back the first sequel, so the current schedule is tenative to say the least.

Cameron explained to Variety that he is prepared to push back the films again, in order to ensure the "cadence" of their releases.

"We haven't moved that target yet, but we will if we need to. The important thing for me is not when the first one comes out but the cadence of the release pattern," Cameron said. "If it's an annual appointment to show up at Christmas, I want to make sure that we're able to fulfill on that promise."

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