The revocation also means Allen will not be participating in this year’s MTV Video Music Awards, for which the singer was nominated in the Best New Artist category.

In a message to fans on her web site, the singer said getting the visa reinstated is taking longer than she expected. The visa was reportedly revoked because of an alleged assault on a photographer earlier this year.

Allen offered apologies to fans and said they should expect her to reschedule the canceled shows as soon as she can.

“I am so disappointed that I won’t be able to come to the States at this time,” Allen said. “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!”