'Pacific Rim 2' will be a "different adventure" to the first movie.
Director Guillermo del Toro has confirmed Charlie Day and Burn Gorman - who portrayed squabbling scientists Geiszler and Gottleib - will be returning for the sequel but they won't be battling the same Kaiju enemy again.
The filmmaker said: "I think that two of our main characters like in the first one are Burn and Charlie.
They are really, really - I mean, honestly, they are probably the guys I have the most fun writing along with Hannibal Chau so just from a purely selfish drive, I like writing them.
"You're gonna get a lot of that, but the Kaijus are very different and you're gonna see a very different type of the robots I think. It's gonna be quite a different adventure."
The sequel is set some time after the 2013 blockbuster and the filmmaker has promised "quite a jump" between the two.
He added in an interview with Collider: "It's a few years after the first one. It's not an immediate follow-up. It is the world having been freed of Kaiju, what happens to the world after - what happens to the Jaeger technology once the Kaiju are not a threat. It's quite a jump."
'Pacific Rim 2' is scheduled for release on April 7, 2017.