LONDON: BARACK OBAMA, US presidential contender, defended his decision to travel to Europe and the Middle East, saying yesterday problems encountered by Americans at home were often best dealt with by working with allies overseas.

Senator Obama told reporters after talks with British Prime Minister Gordon Brown at 10 Downing Street that he wasn't sure if there would be any immediate political impact from the trip.

"The reason that I thought this trip was important is that I am convinced that many issues that we face at home are not going to be solved as effectively unless we have strong partners abroad," he said. The Democratic hopeful seemed relaxed as he strolled down to the Prime Minister's Downing Street office, pausing briefly to shake the hands of two somewhat startled police officers. Mr Brown greeted him just inside the door.

Pooled television images showed Mr Brown offering Senator Obama a chair on the Downing Street terrace before they settled down for two hours of talks.

The pair later took a stroll in the sunshine around Horse Guards Parade, the vast open space where military reviews are often held. Tourists snapped pictures while security guards walked ahead of the two men.

The stroll in the arena offered a photo opportunity for Senator Obama, whose visit to London has been decidedly low-key, particularly after the huge crowds he drew earlier in the week in Germany.

Earlier, he met former prime minister Tony Blair, who is now a Middle East envoy. The meeting lasted for just over an hour.

The Democratic nominee met Mr Blair for breakfast at his London hotel, and chatted with his guest about their children before sending photographers out of the room.

Senator Obama's campaign earlier said he wanted to talk to Mr Blair about Middle East peace efforts after his visits to Jordan, Israel and the West Bank last week.

The Illinois senator's staff said he was also keen to hear Mr Blair's views on climate change, an issue on which he has worked since leaving office last year.

In the US, Republican presidential contender John McCain met the Dalai Lama in Colorado where he urged China to address human rights concerns and free Tibetan prisoners.

"I urge the Chinese leaders to engage in talks and make progress with his holiness's representatives in addressing the just grievances of the Tibetan people," Senator McCain said

The exiled Tibetan leader said the Arizona senator had shown "genuine concern" for human rights, democracy and environmental concerns with regard to China.