President Obama meets with the emir of Qatar, Sheik Hamad bin Khalifa Al Thani, in the Oval Office on Tuesday. The emir is among a series of visiting Middle East leaders urging the U.S. to take a greater role in the Syrian conflict. Jewel Samad/AFP/Getty Images hide caption

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A Syrian rebel patrols the area in the Sheikh Maqsud district of the northern city of Aleppo, on Thursday. Dimitar Dilkoff /AFP/Getty Images hide caption

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John Kerry, on his first trip abroad as secretary of state, walks with French President Francois Hollande after their meeting at Elysee Palace in Paris on Feb. 27. Kerry's nine-day trip took him through Europe and the Middle East. Jacquelyn Martin/AP hide caption

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Secretary of State John Kerry (center, right) meets with members of Egyptian political parties in Cairo on Saturday. Khaled ElFiqi/AFP/Getty Images hide caption

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