WASHINGTON — British Prime Minister Gordon Brown discussed the Iraq war, global warming and his country's relationship with the U.S. as he met with all three presidential candidates, one of whom will be his ally come January.

Republican Sen. John McCain and Democratic Sens. Hillary Rodham Clinton and Barack Obama came off the campaign trail to talk with Brown in a series of sessions.

"I am absolutely confident that having talked to the three candidates that the special relationship between our two countries is strong and secure and valued by all of them,'' Brown said afterward. "I am also absolutely confident that through working with any of them we could rise to the great challenges of the future.''

Brown succeeded Tony Blair last June and is on his second visit to the United States -- and to see President Bush -- as prime minister.

"We think it's probably a wise move by the prime minister to get to know one of the individuals who will be elected president a year from now,'' presidential spokesman Tony Fratto said, acknowledging the next chapter in U.S.-British relations. "It makes sense.''

Before meeting with Bush at the White House, Brown met one-on-one with Obama, then Clinton, then McCain in 45-minute intervals spanning three hours at the British ambassador's residence in Washington. The three were briefed before by their respective foreign policy aides but no staffers were present during the sessions.

Aside from Iraq, the environment and U.S.-Britain relations, Brown also discussed Afghanistan and China with Clinton and Africa with Obama. He and McCain talked about the Arizona senator's call for creating a League of Democracies and Brown's proposal for the World Bank to take on an environmental mission.

It was Obama's first meeting with Brown. McCain met Brown last month during a visit to London, while Clinton and Brown have known each other since her years as first lady.

The talks gave McCain, Clinton and Obama the opportunity to appear presidential alongside a foreign leader; cameras captured each of them with Brown, a member of Britain's Labour Party.

"Britain and America can work well, do work well and will continue in my view to work very well in the future,'' Brown said.

With new leadership already in Britain and upcoming in the United States, relations between the two countries are poised for change.

Bush and Blair had an extraordinarily steadfast bond, strengthened in part by their unwavering support for the Iraq war. However, Bush is highly unpopular in Britain and Blair's political fortunes soured because of the friendship.

In contrast with his predecessor, Brown has taken a more cautious approach with Bush and the relationship grew tense when Britain decided to draw down its troops in Iraq. He has said a plan to reduce British troop numbers from about 4,000 to 2,500 would remain on hold; it was delayed after a recent spike in violence in the southern port city of Basra.

Of the presidential candidates, McCain is a staunch backer of a continued U.S. military presence in Iraq, while Clinton and Obama have called for withdrawing troops.

Republican Sen. John McCain and Democratic Sens. Hillary Rodham Clinton and Barack Obama came off the campaign trail to talk with Brown in a series of sessions.

"I am absolutely confident that having talked to the three candidates that the special relationship between our two countries is strong and secure and valued by all of them,'' Brown said afterward. "I am also absolutely confident that through working with any of them we could rise to the great challenges of the future.''

Brown succeeded Tony Blair last June and is on his second visit to the United States -- and to see President Bush -- as prime minister.

"We think it's probably a wise move by the prime minister to get to know one of the individuals who will be elected president a year from now,'' presidential spokesman Tony Fratto said, acknowledging the next chapter in U.S.-British relations. "It makes sense.''

Before meeting with Bush at the White House, Brown met one-on-one with Obama, then Clinton, then McCain in 45-minute intervals spanning three hours at the British ambassador's residence in Washington. The three were briefed before by their respective foreign policy aides but no staffers were present during the sessions.

Aside from Iraq, the environment and U.S.-Britain relations, Brown also discussed Afghanistan and China with Clinton and Africa with Obama. He and McCain talked about the Arizona senator's call for creating a League of Democracies and Brown's proposal for the World Bank to take on an environmental mission.

It was Obama's first meeting with Brown. McCain met Brown last month during a visit to London, while Clinton and Brown have known each other since her years as first lady.

The talks gave McCain, Clinton and Obama the opportunity to appear presidential alongside a foreign leader; cameras captured each of them with Brown, a member of Britain's Labour Party.

"Britain and America can work well, do work well and will continue in my view to work very well in the future,'' Brown said.

With new leadership already in Britain and upcoming in the United States, relations between the two countries are poised for change.

Bush and Blair had an extraordinarily steadfast bond, strengthened in part by their unwavering support for the Iraq war. However, Bush is highly unpopular in Britain and Blair's political fortunes soured because of the friendship.

In contrast with his predecessor, Brown has taken a more cautious approach with Bush and the relationship grew tense when Britain decided to draw down its troops in Iraq. He has said a plan to reduce British troop numbers from about 4,000 to 2,500 would remain on hold; it was delayed after a recent spike in violence in the southern port city of Basra.

Of the presidential candidates, McCain is a staunch backer of a continued U.S. military presence in Iraq, while Clinton and Obama have called for withdrawing troops.