Deadline has learned that Emmerich and co-writer and producer Dean Devil will have to take on the aliens without Smith, as he has informed 20th Century Fox he won't be joining the sequel, which is scheduled for a July 1, 2016 release. That date marks the 20th anniversary of the 1996 original, which grossed $817.4 million worldwide.
It doesn't mean the movie won't be made, however. Emmerich and Devlin wrote two different versions of the movie – one with Smith and one without him. James Vanderbilt has since been working on the two separate scripts.
Emmerich previously confirmed that a number of the original film's characters appear in the scripts. The 1996 original also starred Bill Pullman, Jeff Goldblum, Randy Quaid, Mary McDonnell, Brent Spiner, James Duval and Vivica A. Fox.