Barry Manilow has been rushed to hospital due to complications from "emergency oral surgery".
The 72-year-old Copacabana singer was taken back to Los Angeles after a sold-out concert in Memphis.
A couple of his shows are being re-scheduled and it is not known whether he will be able to go to the Grammy Awards on Monday, according to his Facebook page.
The statement said: "Following a triumphant sold out concert in Memphis, Barry Manilow was rushed back to Los Angeles due to complications from emergency oral surgery that Manilow had on Monday."
It added: "At this time it is unclear if Manilow will be able to attend the Grammy Awards on Monday February 15 where he is nominated for his 15th Grammy Award for his latest album, My Dream Duets."
Manilow is currently on a tour called One Last Time - One Last Tour throughout North America and the UK.
He is expected to arrive in the UK in June for concerts in Leeds, Newcastle Upon Tyne, Glasgow, Manchester, Birmingham, Cardiff and London.