U2 have cancelled their headline slot at this year's Glastonbury Festival after frontman Bono underwent emergency back surgery.

The band, set for a headline slot at Glastonbury on June 25, has also postponed a US and Canadian tour after the singer suffered temporary partial paralysis before the surgery.

"I'm heartbroken," he said.

"We really wanted to be there (Glastonbury) to do something really special - we even wrote a song especially for the Festival."

Festival founder Michael Eavis said Bono phoned him personally to break the news.

"It was obvious from our telephone conversation that U2 are hugely disappointed," he said.

"Clearly, they were looking forward to playing the Pyramid Stage as much as we were looking forward to watching them.

"At this point, we have no comment to make about possible replacements for U2's Friday night slot.

"Instead, we would simply like to send Bono our very best wishes for a full and speedy recovery."

Rumours have been circulating that Coldplay have been approached to replace the Irish rockers, with second headliner Dizzee Rascal also a possible replacement.