James Gunn insists 'Guardians of the Galaxy Vol. 3' has "basically been finished for years".

The 54-year-old director is set to helm the latest movie in the Marvel Cinematic Universe (MCU) franchise and confirmed that he's completed the vast majority of the film and is now simply making some minor tweaks to the script.

James told Collider: "It's basically been finished for years. I keep fiddling with different things and adding things, and figuring out permutations and stuff – I'm in the middle of doing another draft now – but it's really small stuff in comparison to what it has been.

"It's basically been finished since three years ago."

'The Suicide Squad' director also confirmed that Marvel did not ask him to put any storylines in the new 'Guardians' movie – which is set to begin production later this year – to pave the way for future MCU blockbusters.

James shared: "The only time they ever (asked me to include something for future MCU movies) was on the first movie with Thanos, putting Thanos in there. Which they wanted me to do. But besides that they've never done that.

"I know that the characters have been through certain things, so I have to deal with that stuff. But for the most part, they never once asked me to put anything in the script for 'Volume 3' to set up anything in the future. Nor would I do it, frankly, it's not really my thing."

Despite directing multiple movies in the genre, James recently branded modern superhero films as "mostly boring" and made a bleak prediction for the future.

He said: "We know about the way the cowboy films went, and the way war films went.

"I don't know, I think you don't have to be a genius to put two and two together and see that there's a cycle to those sorts of films, you know, and that the only hope for the future of the comic book and superhero films is to change them up.

"They're really dumb. And they're mostly boring for me right now."