B.o.B and Justin Bieber will perform at this year's MTV Video Music Awards (VMAs) in California, it's been announced.

The pair will join previously announced live acts Kanye West, Drake and Florence and the Machine.

The ceremony takes place at the Nokia Theatre on September 12 and will be broadcast live on MTV.

Presenters on the night include Twilight actress Ashley Green and Ke$ha.

Lady Gaga leads the nominations for this year's VMAs with 13, including Best Female Video, Best Pop Video and Best Dance Music Video.

(by Jason Gregory)