Britney Spears is planning a "spectacular" 30th birthday in December.

The 'Hold it Against Me' hitmaker - who has sons Sean Preston, five, and Jayden James, four, with ex-husband Kevin Federline - insists she is not upset about leaving her 20s behind and is excited to see what the next decade in her life will bring her, with a big party to kick things off.

She said: "I think the older you get, the wiser you get. I can't wait.

"I'm really excited and I am definitely going to celebrate and do something spectacular. I'm going to be in South America so I'll have to do something pretty fun. A carnival of Britney? I don't think I'll be doing that. It'll be something a little bit more low key.

The blonde star is also excited about the forthcoming US version of 'x factor', and is particularly looking forward to seeing music mogul Simon Cowell dish out his withering put-downs.

She told Britain's Glamour magazine: "I'll definitely watch it. I respect Simon's honesty. It's refreshing. But I couldn't be that honest."

Despite turning 30, Britney - who is in a relationship with her former agent Jason Trawick - continues to be under the conservatorship of her father Jamie Spears, which has been in place since a highly-visible public meltdown in 2008, and he is likely to retain control of her affairs for the foreseeable future.

A source said recently: "The conservatorship won't be ending this year because everything is going well.

"Britney is on tour again, which she truly loves. This would be the worst time to make a change, while she is on the road, and is in unfamiliar surroundings."