It has been nearly 17 years since the blockbuster Independence Day opened on the 4th of July in 1996, and, according to director Roland Emmerich, that time frame may come in handy for the two-part sequel ID Forever - Part 1 and ID Forever - Part 2. The filmmaker revealed that the follow-up's story is set 20 years later, centering on a distress call that was made by the first wave of aliens in Independence Day.

"The humans knew that one day the aliens would come back. And they know that the only way you can really travel in space is through wormholes. So for the aliens, it could take two or three weeks, but for us that's 20 or 25 years."

Roland Emmerich wrote the screenplays for both ID Forever - Part 1 and ID Forever - Part 2, with his White House Down writer James Vanderbilt currently performing a rewrite. The director also said that the humans have embraced the alien technology in the years following the initial attack.

"It's a changed world. It's like parallel history. [Humans] have harnessed all this alien technology. We don't know how to duplicate it because it's organically-grown technology, but we know how to take an antigravity device and put it in a human airplane."

Independence Day star Bill Pullman is on board for both movies, although Will Smith has not been confirmed quite yet. The filmmaker revealed this story will focus on a new generation of heroes, including the stepson of Will Smith's character, played by Ross Bagley in the original.

"It's still some of the same characters, but also new younger characters; it's a little bit like the sons take over. The first one ends on a little success, but only enough to give the humans hope. And then in the second one they free themselves again [from the aliens]."

When asked what is left for the aliens to destroy in the sequels, the director gave a cryptic response.

"We've rebuilt. But [the aliens] also do different things."