Britney Spears has confirmed two dates at the O2 arena in London on June 3 and 4.

Fans can register on her official Web site to buy tickets 24 hours before the Dec. 5 on-sale date. AEG Live is the promoter for the shows at the O2, which has a maximum capacity of 23,000.

Spears' new set "Circus" (Jive/Sony BMG) is released in the U.K. on Dec. 1. She is also due to perform on music talent TV show "The X Factor" on Nov. 29.