He said the Writers Guild of America (WGA) strike has meant there is a delay, but added he supported the writers.
In an interview with ET, Pratt said: "We're in the midst of this writers' strike, and so everything has been paused and [put] on hold for the right reasons.
"I really do support the WGA and our writers. When the negotiations have been completed, and the writers feel comfortable moving forward, then it'll be time to start talking about what's next for that.
"We're so grateful for the support, though."
He said he had been surprised by the popularity of the film.
"[It's] really shocking to me how successful that movie's been. I mean, I expected that people would love it the way I was excited about it, but it's truly multigenerational around the world. People love it. They love Mario... It's a really fun, funny, cute, heartwarming movie and, God, I can't believe I'm part of it."
Meanwhile, Pratt has previously spoken about the biggest Super Mario Bros Movie fan there is — his wife, Katherine Schwarzenegger!
Speaking to Digital Spy, he said: "Out of everything I've done, this is the one thing that everyone I know is like, 'You're doing that? When's that coming out? Ooh, I've got to see that. Can I come to the premiere of that?'
"My wife is very, very excited. She grew up playing Yoshi's Story and Mario Kart. She's very excited by it – and saw the movie, and loved it."
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