It also means the band will not be appearing at Glastonbury, one of the biggest live music events of the annual pop calendar.

Bono has been told to recuperate for at least eight weeks and band manager Paul McGuinness, speaking to Reuters outside the Munich hospital where the operation was performed on Friday, said the 50-year-old singer "feels awful" about the tour changes, which will affect over a million fans.

"Clearly this is a serious injury and the recuperation time necessary to rehabilitate Bono is a big problem for the U2 tour and has unfortunately necessitated the postponement of 16 shows in North America," he said.

"Those shows were to occur between June 3 in Salt Lake City and July 19 in Meadowlands Stadium."

The earliest possible date for Bono's return, according to the band's website, would be Aug. 6 in Turin, Italy.

U2 were to have been the headline act on the main stage at Glastonbury on June 25, but that has now been cancelled.

"I'm heartbroken," Bono said in a statement posted on the festival's website. "We really wanted to be there to do something really special — we even wrote a song especially for the festival."

Blow to Live Nation As well as the band and fans, the injury will also hit Live Nation, the music concert company which signed a 12-year deal to handle merchandising, digital and branding rights and touring for one of the world's most successful bands.

"Obviously Bono feels terrible about missing these shows and we are working as fast as we can with Live Nation to reinstate them and reschedule them for next year," McGuinness said.