Barack Obama In London

Queen Elizabeth II sits with G20 leaders, April 1, 2009. Seated front left, Britain's Prime Minister Gordon Brown, and at right Brazil President Luiz Innacio Lula da Silva. Second row, Netherlands Prime Minister; South Africa President Kgalema Motlanthe; U.S. President, Barack Obama. Top from left, Thailand's Prime Minister, Abhisit Vejjajiva; Japan Prime Minister, Taro Aso; Italy's Prime Minister, Silvio Berlusconi.

U.S. President Barack Obama and his wife, first lady Michelle Obama, walk hand in hand as they leave Downing Street, London, after a G20 dinner, Wednesday April 1, 2009.

President Barack Obama and his wife Michelle, pose with Britain's Queen Elizabeth II and Prince Philip, during an audience at Buckingham Palace in London, Wednesday, April 1, 2009.

President Barack Obama shakes hands with China's President Hu Jintao, as Secretary of State Hillary Rodham Clinton looks on at Winfield House in London, Wednesday, April 1, 2009.

President Barack Obama drinks from a bottle of water during a joint news conference with Britain's Prime Minister Gordon Brown, unseen, at the Foreign and Commonwealth Office in London, Wednesday, April 1, 2009.

President Barack Obama meets with David Cameron, leader of Britain's Conservative Party, Wednesday, April 1, 2009, at Winfield House in London.

U.S. President Barack Obama, right, and Russian President Dmitry Medvedev talk during their meeting ahead of the G20 summit in London, Wednesday, April 1, 2009.

President Barack Obama reaches out to shake hands with Britain's Prime Minister Gordon Brown, unseen, at the Foreign and Commonwealth Office in London Wednesday April 1 2009 after a joint news conference. President Obama sought Wednesday to rally the world's top and emerging powers to help cope with a global economic downturn, saying, "We can only meet this challenge together."

Britain's Prime Minister Gordon Brown and U.S. President Barack Obama at a press conference at the Foreign and Commonwealth Office in London Wednesday April 1, 2009.

U.S. President Barack Obama speaks during a press conference at the Foreign and Commonwealth Office in London Wednesday April 1, 2009.

U.S. President Barack Obama, center, walks out with U.S. Treasury Secretary Timothy Geithner, right, following a meeting with British Prime Minister Gordon Brown at 10 Downing Street in London, Wednesday, April 1, 2009. At left are Britain's Foreign Secretary David Miliband and U.S. Secretary of State Hilary Rodham Clinton.

From left to right, British Prime Minister Gordon Brown and U.S. President Barack Obama walk up the stairs at the Foreign and Commonwealth Office Building in London, before the start of their joint news conference, Wednesday, April 1, 2009.

U.S. President Barack Obama waves as he leaves 10 Downing Street in London with British Prime Minister Gordon Brown, unseen, after a meeting Wednesday, April 1, 2009 ahead of the G20 summit.

Britain's Prime Minister Gordon Brown, right, and U.S. President Barack Obama walk away from 10 Downing Street to give a news conference at the Foreign Office in London, Wednesday April 1, 2009.

U.S. President Barack Obama, center, with U.S. Secretary of Treasury Tim Geithner, left, and U.S. Secretary of State Hillary Rodham Clinton, right, in the Cabinet Room inside 10 Downing Street during their meeting with British Prime Minister Gordon Brown in London, Wednesday, April 1, 2009.

British Prime Minister Gordon Brown, right, and U.S. President Barack Obama leave 10 Downing Street in London after a meeting ahead of the G20 Summit, Wednesday, April 1, 2009.

Britain's Prime Minister Gordon Brown, left, looks at the President of the United States Barack Obama, center, shaking hands with PC Michael Zamora, right, a policeman on duty outside 10 Downing Street in London, Wednesday, April 1, 2009.

U.S. President Barack Obama, right, walks with Britain's Prime Minister Gordon Brown, to their joint press conference at the Foreign and Commonwealth Office Building in London, Wednesday, April 1, 2009.

Britain's Prime Minister Gordon Brown, second left, and his wife, Sarah, left, greet U.S. President Barack Obama and his wife, Michelle, outside 10 Downing Street in London, Wednesday April 1, 2009. World leaders are gathering in London for the Group of 20 Summit amid an unprecedented security operation to protect the meeting from violent protests and terrorists.

Britain's Prime Minister Gordon Brown, left, greets the President Barack Obama at Downing Street in London, Wednesday, April 1, 2009.