Manilow's condition was made worse by "high-energy performances"

The 63-year-old star pulled the plug on three appearances scheduled for this weekend and told audiences he was in too much pain to continue, reports AP.

His condition had been "exacerbated by his high energy performances", said his publicist in a statement.

Manilow had already called off 16 shows to coincide with his surgery.

The Copacabana singer will perform at the Emmy Awards in Los Angeles on 27 August, before having surgery in California at the end of the month.

Disappointment

A statement on his website said he planned to return to Las Vegas in November following a period of "intensive recovery".

"On behalf of Barry... we apologise for your inconvenience and the disappointment shared by us all," the statement said.

Earlier this year the veteran performer topped the US album charts for the first time in nearly 29 years.

His latest album, The Greatest Songs of the Sixties, is released in mid-October.

It features cover versions of the Righteous Brothers' You've Lost That Lovin' Feeling and the Beatles' And I Love Her.

Best known for hits like Mandy, Copacabana and Looks Like We Made It, Manilow has sold more than 70 million records worldwide.