U.S. presidential candidate John McCain met Thursday with British Prime Minister Gordon Brown and told reporters afterwards that "al-Qaida is on the run" in Iraq.  He also warned against a withdrawal from Iraq and allowing al-Qaida to declare victory. Tendai Maphosa has more in this report from the British capital.

US Republican presidential candidate John McCain (L) meets with British PM Gordon Brown at 10 Downing Street in central London, 20 Mar 2008

As the Iraq engagement entered its sixth year, Republican presidential hopeful John McCain said that the "surge" of increased U.S. troop levels was succeeding in bringing stability to Iraq and that the strategy must continue.

Senator McCain, who has been on a weeklong congressional "fact-finding" tour that has taken him to Iraq for the eighth time, said Iraq would likely be the key issue of the U.S. presidential election.

The Republican candidate thanked Britain for its support in Iraq and for "the enormous service and sacrifice" that its military men and women have made there and in Afghanistan.

"I fully appreciate that British public opinion has been frustrated by sometimes our lack of progress in both areas, but all I can do is express my gratitude to the British government and people and especially the young people who are serving," he said.

Britain has remained the U.S. government's closest ally in Iraq, although its continued military presence there is unpopular at home. It currently has about 4,000 troops stationed in southern Iraq but plans to reduce that to about 2,500 later this year. It has reduced troop levels in the last two years, as its military commitment in Afghanistan has increased.

McCain also expressed appreciation for Mr. Brown's leadership in tackling climate change. He said he is committed to address the issue of climate change comprehensively and globally but insisted China and India must be part of a global agreement on the issue.

"I want to make [it] clear again, we will not have a global agreement that is effective unless India and China are part of it," he added.  "I think that there will be sufficient International pressures and domestic pressures as well as the facts of the environmental challenges that will bring them into a global agreement."

Before his stop in London McCain, who is a senior member of the Senate Armed Services Committee, visited Iraq, Jordan and Israel. From London he is expected to go to Paris to meet with French President Nicolas Sarkozy.