Kelly Clarkson won't join 'American Idol' because she wants to spend more time with her kids.

The 42-year-old pop star has been tipped as a possible replacement for Katy Perry on the show's judging panel, but Kelly insists that she can't commit herself to the programme.

Kelly - who has River Rose, nine, and Remmington, eight, with her ex-husband Brandon Blackstock - told 'Entertainment Tonight': "I can't do that, only because I promised my kids.

"I was like, 'I wanna be there as much as I can.' And it would put me in Los Angeles, and that's why I had to quit 'The Voice', which ... I love that team."

Kelly previously served as a coach on 'The Voice', while she also won the first season of 'American Idol' back in 2002.

Meanwhile, Katy previously argued that a female star should replace her on the 'American Idol' judging panel.

The 39-year-old pop star believes there should always be a female voice on the 'American Idol' panel.

The 'California Gurls' hitmaker - who starred on the hit TV show alongside Lionel Richie and Luke Bryan - told E! News: "That would be too many men, let's be honest.

"But we love Jelly Roll, and I'd love for him to be on this show whenever it's appropriate."

Katy also stressed that her replacement needs to be someone who is "honest and bold, not scared of negative comments".

What's more, the singer suggested that she's faced more scrutiny than her male co-stars.

Katy - who is in a long-term relationship with movie star Orlando Bloom - said: "When you have an opinion, when you're bold, when you're a female, it just happens."