Pop star Lily Allen has postponed her US tour and cancelled an appearance at the MTV Music Awards after her US work visa was revoked earlier this month.
Her tour was due to begin in San Diego on 6 September but a record company spokesman said reinstating the visa was "taking longer than anticipated".
The visa was cancelled after Allen flew into Los Angeles and was questioned over an assault in London.
"I'm so disappointed. I'll be back as soon as I can," said the singer, 22.
Her spokesman denied she had been dropped from the MTV ceremony in Las Vegas on 9 September.
He said her manager had informed MTV about the situation.
"She was not dropped from the awards and MTV are hugely disappointed that she will not be able to participate," he said.
The singer, whose hits include Smile, is nominated for best newcomer.
"I was really looking forward to playing these shows and being part of the video music awards," Allen said.
The singer had previously said she would do "everything I can" to honour the US tour dates.
Earlier this year, Allen postponed a string of other dates in the US saying she was "bored" and wanted to concentrate on her second album.
She was arrested following an incident outside a London nightclub in March and this resulted in a caution for common assault.
Allen is due to perform at this weekend's V Festival after pulling out of several other European festivals due to illness.