Chris Pratt is "really proud" of his voice work on 'Super Mario Bros.'.

The 43-year-old actor's casting as Nintendo's beloved plumber Mario has caused controversy because the character is Italian and now the star has opened up about the backlash and urged fans to watch the movie first, teasing he's been able to offer something "unlike anything you've heard in the Mario world before".

He told Variety: "I worked really closely with the directors and trying out a few things and landed on something that I’m really proud of and can’t wait for people to see and hear.

“It’s an animated voiceover narrative. It’s not a live-action movie. I’m not gonna be wearing a plumber suit running all over.

“I’m providing a voice for an animated character, and it is updated and unlike anything you’ve heard in the Mario world before.”

Chris Meledandri, the founder of Illumination - who are making the film with Universal - has also defended the 'Guardians of the Galaxy' actor's casting.

He said: "Chris was cast because we felt he could give a great performance as Mario. And now that we’ve done about 15 recording sessions, and the movie is three-quarters done, I sit here and say that I love his performance as Mario.

"[Considering I have] Italian American heritage, I feel I can make that decision without worrying about offending Italians or Italian Americans. … I think we’re gonna be just fine. Especially because (Pratt has) given such a strong performance.”

The star-studded voice cast for the movie also includes Charlie Day (Luigi), Anya Taylor-Joy (Princess Peach), Jack Black (Bowser), Seth Rogen (Donkey Kong) and Keegan-Michael Key (Toad).

It was recently confirmed the film has been pushed back from a release of December this year and will now hit cinemas next April.