According to TMZ, the 'Toxic' singer hadn't officially signed up for the show as of Friday morning, despite numerous reports claiming otherwise.
The final details of the rumoured $15m deal were reportedly being worked out before her co-conservators - father Jamie Spears and fiancé Jason Trawick - sign the contract, which will most likely occur over the weekend.
Spears will allegedly travel to New York as she believes personally appearing at the event will create a buzz for the show's second season.
Demi Lovato is rumoured to be the other female judge, after Nicole Scherzinger and Paula Abdul were axed from the panel.
Chaka Khan is also lobbying producers to become a judge on The X Factor USA.
Watch Britney Spears in her video for 'Till The World Ends' below: