Iggy Azalea and Ariana Grande

Iggy Azalea and Ariana Grande pose in the VIP Glamour Pit during the MTV EMA's 2013 at the Ziggo Dome on November 10, 2013 in Amsterdam, Netherlands. 

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The 2014 Billboard Music Awards has a huge problem on its hands. Breakout stars Ariana Grande and Iggy Azalea will perform their hit single "Problem" at this year's ceremony, being held on Sunday, May 18 in Las Vegas. Azalea is also scheduled to perform her song "Fancy" during the live ABC telecast.

Grande and Azalea join previously announced performers including Miley Cyrus, Ricky Martin, Jennifer Lopez, Pitbull, 5 Seconds of Summer, Florida Georgia Line, Jason Derulo, Imagine Dragons, Luke Bryan, John Legend and OneRepublic. Lorde will perform her new single "Tennis Court" for the first time on television, and Miranda Lambert and Carrie Underwood will do the same with their duet "Somethin' Bad."

It's been a monumental year for Grande, whose "Problem" bowed at No. 1 on Billboard's Digital Songs chart and No. 3 on the current Hot 100 -- the highest debut of the year on both charts. The track is the first single off Grande's upcoming second album, due out in the fall. In addition to performing at the BBMAs, Grande is a finalist for the Top New Artist award.

Azalea's "Fancy," featuring Charli XCX, currently stands at No. 4 on the Hot 100. With "Problem at No. 3, Azalea is the first female rapper ever to have two songs concurrently in the top five of the Hot 100 chart.

Fan voting for the 2014 Milestone Award presented by Chevrolet will continue through the first two hours of the awards show, ending at 10pm ET. To vote for finalists Ellie Goulding, OneRepublic or Carrie Underwood go to billboard.com/milestone.

The BBMAs, which are produced by dick clark productions, will be broadcast live from the MGM Grand Garden Arena in Las Vegas on Sunday, May 18, on ABC at 8 p.m. ET. Yahoo will be streaming this year's red carpet show. For additional information on the 2014 Billboard Music Awards visit us at billboardmusicawards.com or the Billboard hub at billboard.com/bbma.