Britney Spears and Demi Lovato have been officially confirmed as X Factor judges.

The pop singers will join Simon Cowell and L.A. Reid on the panel of the US version of the TV talent show as replacements for Nicole Scherzinger and Paula Abdul, it was announced at Fox's Upfront Presentation at the Beacon Theatre in New York today.

"I couldn't be more excited to join The X Factor judging panel. I'm a huge fan of the show and now I get to be a part of the action. Simon and L.A. better watch out," Britney said in a statement.

Demi described her new role as a dream come true: "I'm so thrilled to join this legendary group of judges on the show. To be able to spend each week with Simon, L.A. and Britney watching the best that America has to offer is truly a dream come true."

Shortly before the official announcement, Britney - who is rumored to have agreed a $15 million deal to be a judge on the show - tweeted a picture of herself with her fellow judges, captioning it "#britneyxfactor #SimonBritneyDemiLA."

Simon also took to his Twitter page to express his excitement at the decision. "Can't believe it's finally happened. Very exciting!" he wrote.

A new host for the show has yet to be announced after Steve Jones was axed after just one series.

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