US Republican presidential hopeful John McCain praised Britain's "strong commitment" to the conflicts in Iraq and Afghanistan in talks with Prime Minister Gordon Brown and Conservative opposition leaders in London Thursday, according to dpa. Speaking to journalists after his meeting with Brown in Downing Street, McCain paid tribute to the "sacrifice" of British troops in the two conflicts, but also said he understood the "frustrations" of the British public at the slow progress in restoring security. Brown's spokesman said the two men had wide-ranging discussions which also covered issues such as climate change, the reform of international institutions, development, the Middle East conflict and the global economy. "The prime minister made clear in particular his commitment to the importance of the relationship with the United States, which he considers to be our most important bilateral relationship," said the spokesman. On Iraq, McCain took the view that the terror network al- Qaeda was "on the run" but not defeated. He reaffirmed his belief that the US troop "surge" in Iraq had proved a success. "Al-Qaeda is on the run. They are not defeated. We're going to have to continue training the Iraqi military and do what we have been doing if we are going to achieve a stable situation in Iraq," he said. McCain also had talks with David Cameron, the leader of Britain's opposition Conservative Party, who said he had a "fascinating and very productive" meeting with the Republican politician. McCain, who stopped over in London on his return from a whistle- stop tour of the Middle East that took him to Israel, Jordan and Iraq, is due to visit Paris later.