A day after the Vice Presidential debate, Republican presidential hopeful Mitt Romney is taking aim at Joe Biden -- accusing the vice president of contradicting the State Department on the deaths of four Americans killed when the U.S. consulate in Libya was attacked.

(SOUNDBITE) (English) REPUBLICAN PRESIDENTIAL NOMINEE MITT ROMNEY SAYING:

"The vice president directly contradicted the sworn testimony of State Department officials. He's doubling down on denial and we need to understand exactly what happened as opposed to have people brush this aside. "

When asked whether the Benghazi compound had asked for more security ahead of the September 11th attack, Biden said the administration did not know more security was requested -- contradicting sworn testimony from two State Department officials.

Secretary of State Hillary Clinton says details are still sketchy:

(SOUNDBITE)(English) U.S. SECRETARY OF STATE HILLARY CLINTON SAYING:

"To this day, to this day, we still do not have a complete picture, we do not have all the answers. No one in this administration has ever claimed otherwise."

U.S. Ambassador Christopher Stevens and three other Americans were killed in the attack.