Demi Lovato has tipped Lady Gaga to become a new X Factor USA judge.

The TV talent show is currently without two of its judging panel after Britney Spears and LA Reid jumped ship following the conclusion of its 2012 series.

That leaves just Simon Cowell and Lovato as judges - and the latter wants to see Lady Gaga fill up one of the empty chairs. She told Extra:

"I would love to see Lady Gaga. I don't know if that is possible or not."

Gaga's future plans are in doubt, however, after the singer cancelled all of her remaining North America tour dates this year.

The singer pulled the dates after revealing that a joint complaint was more severe than first thought - meaning the 'Born The Way' star needs hip surgery.

2013 looks a bit more promising for Lovato, however, with the singer recently confirming plans to release new single 'Heart Attack' in March.