British pop singer Lily Allen postponed her U.S. tour on Friday after failing to get a new work visa in time, while her rival Amy Winehouse put all her touring commitments on hold to deal with “health issues.”

Allen and Winehouse, who have reputations as wild women in Britain, have been nominated for awards at next month’s 2007 MTV Video Music Awards.

Allen’s U.S. visa allowing her to work temporarily in the country was revoked this month after the 22-year-old was detained for five hours at Los Angeles International Airport when she arrived from Australia.

The singer said she had no idea why she lost her visa. British media reported she had been detained in connection with her arrest in June after an incident outside a London nightclub in March. She received a warning from police but was not charged with any crime.

“I am so disappointed that I won’t be able to come to the States at this time,” Allen said in a statement on her Web site www.lilyallenmusic.com.