Britney Spears doesn't have "anything to prove".

The 'Hold it Against Me' hitmaker kicked of the European leg of her tour promoting seventh album, 'Femme Fatale' in St Petersburg, Russia, last night (22.09.11) and after selling over 70 million albums in her career so far, she doesn't feel pressure to do anything more than have "fun" on stage.

She said: "I don't really have anything to prove at this point. I just do it for fun and see what happens.

"I have a good group of people around me. We have the show at a certain time every night. And we just try to stay consistent on having a routine and staying fit and healthy."

Britney also promised the stage show for the Femme Fatale Tour is as lively as ever.

She said: "The show is really fun for me, it's one of the most entertaining shows that I've ever done. There are six or seven costume changes, the dancers are just on fire and it's a lot of fun. It's a fun show."

The singer is set to turn 30 in December, but isn't worried about reaching the landmark age, as she feels is growing all the time.

She added: "I hear the older you get, the wiser you get and the more you know what you want. Hopefully it'll be a good year."