The band kicked off a six-date residency at the O2 Arena in the British capital, marking the first stop on the U.K. leg of their world tour.

During the show, images of war-torn Syria were shown on the big screens, and frontman Bono praised British politicians for helping refugees and hailed policies to help the poor at home.

Bono backed Britain for its "generosity" in the "fight against extreme poverty", according to the Press Association.

"There are a lot of countries that say a lot, there are a lot of countries that do a lot," he added. " This is a country that does both. What you are doing to transform lives around the planet, you cannot know. You should be very proud of what we're achieving. This is a great country. That's part of what makes Great Britain great - its generosity and its inclusiveness."

After wrapping up the O2 Arena dates on 3 November (15), the band's iNNOCENCE + eXPERIENCE Tour is due to head to cities including Belfast in Northern Ireland and Glasgow, Scotland.

The tour kicked off on 14 May (15) in Canada.