Pregnant singer Alicia Keys has posed nude with a peace sign scrawled on her baby bump to promote her new charity campaign.

The 33-year-old star is expecting her second child with her producer husband Swizz Beatz and she proudly showed off her bulging belly in a nude snap for the #WeAreHere movement.

Keys hopes the drive will rally her fans against social injustices through her music and online media, explaining to the New York Times, "I want to gather an army... It's time to get people's attention. People won't be able to ignore this visual (nude picture)."

The Fallin' hitmaker is kicking off the campaign by donating $1 million and she has named her new song We Are Here.