Justin Bieber "Not Worried" About Sharon Osbourne's Prediction His Career Won't Last

15 October 2012, 08:51 | Updated: 15 October 2012, 09:21

The 'Never Say Never' star has tweeted about predictions his career will fade out over the next few years.

Justin Bieber has responded to Sharon Osbourne's recent comments that he won't "stand the test of time", by insisting he is not worried about the future of his music career.

The 'Boyfriend' star spoke out on Twitter about the former X Factor UK judge's claims that his fans are growing up faster than he is, and promised he doesn't mind it when people "doubt" him.

"For me Justin is , I've met him, I've worked with him, I did a TV commercial with him," Sharon revealed, during the National Radio Conference in Sydney, Australia last week.

"But his problem [is] he's a little guy. His fans are growing up, they're 18, 19 year-olds now," she explained.. "You know, they're young women. And he still looks like that little boy!

"I just don't think, from my gut, maybe my gut's wrong 'cos it's not 100%, but I don't think he's going to stand the test of time," Sharon added.

"Doubt me…I like it," Justin tweeted last night (14th October), in response to Sharon's comments. "Not worried sharon…".

Last week saw Justin Bieber unveil the long awaited music video for 'Beauty And A Beat', his team-up with rapper Nicki Minaj.

Check out a picture of Justin Bieber and Nicki Minaj in the video for his new single 'Beauty And A Beat' below:

The song's video revealed that Justin's recent claims of "personal footage" being stolen were a publicity stunt to promote the video's release.

Justin Bieber's 'Believe' world tour continues this week with shows in Canada.