Credit: Jason LaVeris/FilmMagic

Britney's back!

Sources tell Us Weekly that Britney Spears is heading to Las Vegas this weekend to perform live at Sunday's 2011 Billboard Music Awards.

The 29-year-old pop star will take the stage two times.

Spears will do one performance -- potentially the opening number -- with Rihanna, 23. The duo will perform Rihanna's hit song "S&M." 

Spears will also be performing for the first time ever with Nicki Minaj, 26. Spears and Minaj will partner up for a remix of Spears' hit "Till The World Ends." 

Minaj first met Spears in April. Later that month, Spears confirmed on her website that Minaj would be joining her Femme Fatale tour this summer. 

"I'm obviously honored to be out with Britney," Minaj told Us of the tour. "She's freakin' paved the way for so many things right now in pop culture. I'm excited to be on with her."

So what will Spears' return to the live television be like? "It's gonna be big," a source says. "People will definitely be talking about it the next day."

The 2011 Billboard Music Awards air Sunday night at 8:00 p.m. on ABC.