Amy Winehouse will not be appearing at the MTV Music Awards next month, her US record label has confirmed.
Friends and family have expressed concern over Winehouse's health
Universal Republic Records said all of the singer's US appearances had been cancelled "in a continued effort to support Amy Winehouse's well-being".
Winehouse has reportedly spent several spells in rehab, and her family has expressed concern over her drug use.
She is nominated for three MTV awards, including best female, and was due to perform at the show on 9 September.
Over the last few weeks, the singer has pulled out of several gigs - including two shows with the Rolling Stones and the V Festival - citing exhaustion.
Her September tour of the US and Canada has also been postponed until 2008.
But organisers of the Mercury Music Prize say they still hope the singer will appear at the ceremony, which takes place in London next week.
Back to Black, her hip-hop tinged soul album, is one of the favourites to take home the prize.
Doctors ordered Winehouse to rest earlier this month after she was taken to hospital in London.
The star, who has spoken openly about her past battles with eating disorders and her penchant for alcohol and marijuana, then reportedly went into rehab with her husband, Blake Fielder-Civil.
Speaking to BBC Radio Five Live earlier this week, Fielder-Civil's mother said she feared for the couple's health if they continued to take drugs.
"I think they both need to get medical help before one of them, if not both of them, eventually will die," said Georgette Fielder-Civil.
Winehouse's father, Mitch, countered that his daughter was not in "imminent danger of death".
"Physically she's not fantastic. She lost a lot of weight but I think the eating disorder has been worked on and she's put on a stone. In maybe eight days, that's pretty good," he said.
Winehouse and Fielder-Civil have been photographed this week on holiday in the Caribbean.
Mitch Winehouse said his daughter had sent him a text message from St Lucia to say: "I'm as right as rain."
The 56-year-old told BBC Radio 1: "It was great to hear from her and she seems to be doing OK.
"But then again, we're not there so we don't know what's going on."