Amy Winehouse's U.S. and Canadian fall tour has been canceled in the name of her physical well-being. "Plans are being made to reschedule her U.S. tour for early 2008," reads a statement from the singer's rep. "Until then, Amy has been ordered to rest and is working with medical professionals to address her health." Winehouse recently went through a highly publicized bout of "exhaustion" (which may very well have been a drug overdose) and subsequent hospitalization in London. The singer is scheduled to tour Europe and the U.K. later in the fall, and those dates are still scheduled ... for now. However, it looks like the nixing of her North American trek may mean Winehouse won't be showing up at September 9th's MTV Video Music Awards, where she is nominated for three Moonmen. Fellow headline-making British star Lily Allen -- who will also be absent from the Las Vegas awards show thanks to visa issues -- was recently criticized for toasting the troubled songstress onstage. Allen has defended herself, saying, "Me raising a drink to Amy was just that, showing my support for her. I've been around enough substance abuse and alcoholism to know that it's a serious matter."