Justin Bieber doesn't want to be "just another teen heartthrob."

The 18-year-old singer kicks off a gruelling world tour later this month and is determined the shows will take him to the "next level" and silence any of his critics.

He said: "I don't want to be just another teen heartthrob. I know some people are waiting for me to fail, thinking, 'Oh, his time's up.' Well, I like being the underdog, and this tour is my chance to take things to the next level.

"I've never put in more hours preparing, because I want [the tour] to be perfect. I want it to be an event.

"I'm with a personal trainer every day. I'm rehearsing every day. I want people to see this tour and go, 'Wow, that was something I didn't expect.' "

The 'Never Say Never' hitmaker is taking inspiration from the late Michael Jackson in his preparations for the 'Believe' tour.

Bieber added in an interview with USA Today newspaper: "I've been watching videos of his concert tours over and over, he's my inspiration.

"When my team gets together, we're always asking, 'What would Michael do?' "