09/29/2008 at 02:00 PM EDT
says her new song, "Womanizer" – which debuted on Friday
– is an empowering anthem for girls.
"It's basically saying, 'We know what you're up to.' It's about guys cheating on girls," the singer told New York's Z100 radio station
on Monday. "It's a girl anthem. That's why I like it."
The song is the first single from Spears's upcoming album
, due for release on Dec. 2, her 27th birthday.
As for her recent victory
at MTV's Video Music Awards, where she won three Moonmen (including video of the year for "Piece of Me"), Spears expressed surprise.
"It's a cool video, but I think by far I've done videos that are way better, so I was really shocked that it got the award," she said. "It was just inspiring, though, because now, going forward with the videos that I'm doing now, I can really go there and do something crazy and see what happens."
Another part of the singer's comeback? A tour is "definitely" in the works, she said. "Oh, definitely next year," she said on the radio show. "Probably around the world."
To listen to the complete interview, visit the Z100 Web site.RELATED GALLERY:
2000: Brit causes a stir with her first single!