Lily Allen's battle to renew her U.S. visa has forced her to cancel a series of concerts next month (Sep07). The singer was allowed to enter the country earlier this month, but officials refused to renew her visa, reportedly because of her assault on a photographer earlier this year (07). Now back in London she has been forced to cancel a string of gigs on the America's west coast next month because "the (visa) reinstatement process has proven lengthier than anticipated," according to a statement from concert presenter Live Nation. Allen says, "I am so disappointed that I won't be able to come to the States at this time. I was really looking forward to playing these shows and being part of the Video Music Awards. I want my fans to know that I'll be back as soon as I possibly can!"