U.S. President Barack Obama reacts after answering questions about the attack on the U.S. embassy in Benghazi, Libya, during a joint news conference with Britain's Prime Minister David Cameron (not pictured) in the East Room of the White House in Washington, May 13, 2013. REUTERS/Jonathan Ernst (UNITED STATES - Tags: POLITICS)
U.S. President Barack Obama reacts after answering questions about the attack on the U.S. embassy in Benghazi, Libya, during a joint news conference with Britain's Prime Minister David Cameron (not pictured) in the East Room of the White House in Washington, May 13, 2013. REUTERS/Jonathan Ernst (UNITED STATES - Tags: POLITICS)