Usher and Shakira to become mentors on The Voice USA Stars will replace Christina Aguilera and Cee Lo Green

New mentors ... Usher and Shakira join The Voice USA

POP superstars Usher and Shakira are joining The Voice USA.

R&B star Usher and Colombian singer Shakira will replace mentors Christina Aguilera and Cee Lo Green for the fourth season of the show.
Genie in a Bottle singer Christina, 31, is taking a break to tour her new album.
Forget You star Green, 38, is stepping down for the season to develop new music and a sitcom based on his life.
Usher, 33, and 35-year-old Shakira will join original coaches Adam Levine from Maroon 5 and country music singer Blake Shelton.

Original line-up ... Cee Lo Green, Christina Aguilera, Adam Levine and Blake Shelton

Christina said: "As I have expressed since day one of the show... I am a singer and performer first and I am so excited to get back to that love."
She confirmed that she would be eager to return to The Voice in the future as did Green who said he will be back for series five.