Last month's deadly attack in Libya has become the focus of the presidential campaign today.

U.S. Vice President Joe Biden speaks during the vice presidential debate (Alex Wong/Getty Images)

Mitt Romney is accusing Vice President Joe Biden of "doubling down on denial" in last night's debate when he said "we weren't told" about requests for more security at the U.S. consulate in Benghazi. At a campaign event in Richmond, Va., Romney says Biden's statement is at odds with State Department testimony and Americans "have a right to know what's going on."

The White House says overseas security matters are handled by the State Department. Spokesman Jay Carney says Biden was speaking just for the White House, for himself and the president.

Secretary of State Hillary Rodham Clinton says the precise details of the Benghazi attack are still unclear. But she says the Obama administration is committed to uncovering the truth.

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