Irish rockers U2, from left, Adam Clayton, the Edge, Bono and Larry Mullen, filmed and posted on their website a short video message thanking fans for their support this summer amid Bono's back injury. (Peter Morrison/Associated Press)

U2 has announced a new slate of North American concert dates, making up for the series that was cancelled this summer because of frontman Bono's emergency back surgery.

The Irish rockers will reprise the North American leg of their 360 Degrees Tour beginning May 21, 2011, in Denver, the band and concert promoters Live Nation said Tuesday.

The band filmed and posted a video message on its website thanking fans for their support in "our hour of need," according to Bono.

"[I] really wanted to apologize for the trouble that this injury has put you all through — those of you who bought tickets, organized hotels and travel plans. It's a very big deal," he said in the video.

The back injury he suffered in May — which happened the day after his 50th birthday, he added — was "quite serious" and required emergency spinal surgery in Munich.

'Great songs'

U2 was forced to cancel 16 concert dates across the U.S. and Canada, including stops in Edmonton, Toronto and Montreal. The band also withdrew from a much-anticipated headliner gig at the U.K.'s Glastonbury Music Festival.

However, Bono said the band was eager to return to the stage and hinted that they might debut "some great songs" they've been recording recently in studio.

"There's nowhere else we want to be than with the people who gave us this job," he said.

The rescheduled dates are listed on the U2 website.

U2 returns to touring — in Europe — with a concert in Turin, Italy, on Aug. 6.

U2 will resume its tour, performed on a 360-degree stage, in Europe in August. (Leon Neal/AFP/Getty Images) With files from The Associated Press