Justin Bieber, Lady Gaga and Michelle Obama are giving a helping hand to Beyonce.

Obama and the pop stars have signed on to support Beyonce and the global campaign for World Humanitarian Day, which is Sunday.

The campaign asks that on Sunday people help others through such acts as making sandwiches for the homeless or volunteering at a local charity. The goal is to share 1 billion messages of hope.

A representative for Beyonce says that Bieber, Gaga, Obama, Rihanna, Shakira, Jay-Z, Gwyneth Paltrow, Chris Martin and others will participate.

Beyonce performed her song "I Was Here" at the United Nations in New York last week to promote World Humanitarian Day. The performance was taped and the music video will debut Sunday. The song is from her latest album "4."