U.S. Secretary of State Hillary Clinton and British Foreign Secretary David Miliband (shown here Jan. 21 in Washington, D.C.) will be among the officials meeting in London this week to discuss Afghanistan and Yemen. Joshua Roberts/Getty Images hide caption

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Haiti's President Rene Preval answers questions from the press as Secretary of State Hillary Clinton looks on in Port-au-Prince on Saturday. Preval and Clinton met to discuss the state of emergency after last week's deadly earthquake. Julie Jacobson/AP hide caption

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President Obama speaks from the Rose Garden as George W. Bush and Bill Clinton look on. Obama asked the former presidents to help with U.S. relief efforts in Haiti after the earthquake. Alex Brandon/AP hide caption

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Secretary of State Hillary Clinton listens to remarks by Jordanian Foreign Minister Nasser Judeh after their meeting Friday at the State Department. Tim Sloan/AFP/Getty Images hide caption

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