The singer said she feared she woudn’t be a natural for the job but it’s too big an opportunity to turn down.
'I don't think I am that good at being a judge,' she said. 'I am much more comfortable performing on stage.'
She told a US newspaper: 'If Simon Cowell were to approach me I would really have to think about it because it is a huge commitment. I would definitely be open to it.'
She will battle Cheryl Cole – still relatively unknown in the States – for the job on the American version of Simon Cowell’s television talent show, set to launch in September 2011.