(Editor's note: After this story published, it was announced that Jesse McCartney's role in "The Last Airbender" will be taken by Dev Patel, as McCartney's tour dates left him unable to commit to the film or its boot camp.)
"I heard a lot about this online," McCartney said, referring to fans' criticism. "There's a lot of hard-core fans out there [who] probably know more about it ... I'm still learning. This is M. Night's vision and this is what he wants. To all the fans, I can tell you I'm putting my best foot forward."
That foot forward includes intense kung-fu training for McCartney, who described his character as "an expert firebender." "I've been in kung-fu training for the last month and half-learning all the moves. I'm looking forward to it."
Although he is still learning all about the popular cartoon that first made its debut in Asia before gaining popularity in America, it was his little brother who was already a fan when McCartney signed on to the flick. "I heard about the series from my little brother who's an avid 'Avatar' fan," he explained. "I heard about the project, and that Night was directing it. He flew me out to Philly to read with him. I worked with him a lot on the character. He called me on my phone and was like, 'I want you to play this character.' And we took it from there."
McCartney is also looking forward to working with Rathbone — who will also be filming "New Moon" this year — on the movie. "He was there for the reading and he and I have been in training together. We're flying in a few weeks to start production and then to Greenland to start filming. He's a super nice guy. We've been getting along great."
As for any musical collaboration between the two, McCartney assures us that they'll have plenty of time to mull that over as they film the movie. "We haven't talked about that yet," he said. "I'm sure I'll get to know all of this about him."
[This story was originally published at 6:29 pm E.T. on 1.30.09]
Check out everything we've got on "The Last Airbender."
For breaking news, celebrity columns, humor and more — updated around the clock — visit MTVMoviesBlog.com.