Jurassic World: Rebirth writer David Koepp has said Steven Spielberg was "deeply involved" in making the movie.

The 78-year-old director helmed the original 1993 film Jurassic Park, its 1997 sequel The Lost Work: Jurassic Park and has served as an executive producer on the Jurassic World series ever since, and Koepp - who wrote the first movie and its follow-up - revealed one of the main reasons he returned for Jurassic World: Rebirth was because Spielberg was "very involved" in it.

Speaking to Deadline about Spielberg, the 62-year-old scribe said: "Oh, he was very involved.

"That was one of the reasons I most wanted to do it. Because Steven was deeply involved from the beginning, and for the six months that we were working on the script, it was really just him and me.

"I'd send him my ideas, and we'd work on them, and when you have Steven's full attention, the results can be pretty spectacular."

Jurassic World: Rebirth - which stars Scarlett Johansson, Jonathan Bailey, and Mahershala Ali - follows a team of covert operatives on a mission to stop a rogue biotech organisation from unleashing weaponised dinosaurs around the world.

As the chaos escalates, the team uncovers a dark secret connected to the original Jurassic legacy.

Koepp previously said Jurassic World: Rebirth - which was directed by Gareth Edwards and releases on July 2, 2025 - would capture the "spirit of the first movie".

He told TheWrap: "[We were trying to evoke] the spirit of the first movie, which is the tone that we would like to get closest to."

The writer added it was "the idea of starting afresh" which convinced him to return to the Jurassic series.

He said: "You don't often get that chance, where they give you very few guidelines, except there must be dinosaurs in it."

Even so, before he agreed to come back for Jurassic World: Rebirth, Koepp had a list of demands he gave to Universal Pictures that the studio had to meet.

He explained: "Number one was - the events of the previous six movies cannot be denied or contradicted, because I hate a retcon.

"[Number two was] all science must be real. [Third was] humour is oxygen."

Reflecting on returning to the Jurassic series, Koepp said it was "weird and trippy" for him to step back in time for Jurassic World: Rebirth.

He explained: "It even smelled the same. It felt low pressure, even though Universal might be horrified to hear that."

Looking back at Jurassic Park and The Lost World, Koepp said "writing those first two movies were some of [his] favourite experiences in [his] career so far".

He added: "The combination of grand adventure and real science is right up my alley. And it was fun to be able to decide on a new tone, because every three movies seems like a good time to change tone and characters in a franchise.

"It was great to be able to work solely with Steven and make up a story and think of all new characters and all in a different tone."