Singer Winehouse puts North American tour on hold

Chart-topping British singer Amy Winehouse has put her North American tour on hold, raising more concerns about her health.

"Due to the rigours involved in touring, Amy Winehouse has been advised to postpone her upcoming September U.S. and Canadian tour dates," the British singer's publicist, Tracy Miller, said in a statement Tuesday.

"Amy's European and U.K. tour dates in October and November remain in place. Plans are being made to reschedule her U.S. tour for early 2008. Until then, Amy has been ordered to rest and is working with medical professionals to address her health."

Last week, it was announced that the 23-year-old was cancelling all her August performances because of "severe exhaustion." While British tabloids have claimed the retro-soul singer has been in rehab because of drug abuse, her spokeswoman has denied such claims.

Winehouse made her U.S. debut this year with the acclaimed album Back to Black, but her celebrity has been fuelled by her tabloid image as much as her talent.

She's spoken openly about her past battles with drugs and her penchant for alcohol and marijuana, and her hit single Rehab is an autobiographical tale of her resistance to being pushed to go to rehab.

Winehouse is scheduled to appear at the MTV Video Music Awards on Sept. 9 in Las Vegas, but it is unclear if she will be on hand.