Republican presidential nominee Mitt Romney has accused the Obama administration of contradicting itself and "doubling down on denial" about the true origins of the assault on the US Consulate in Benghazi that killed American envoy to Libya.
"He is doubling down on denial," Romney said at a campaign event in Virginia referring to Vice President Joe Biden's remarks in which the blamed administration's shifting explanations on US intelligence agencies.
"Yesterday I raised some questions about Benghazi and the tragedy that occurred there. There were more questions that came out of last night because the vice president directly contradicted the sworn testimony of State Department officials," he alleged.
"We need to understand exactly what happened, as opposed to just have people brush this aside. When the vice president of the United States directly contradicts sworn testimony of State Department officials, American citizens have a right to know just what's going on. And we're going to find out. And this is a time for us to make sure we do find out," he said.
"After trying for weeks to portray the deaths in Benghazi as part of a larger failure of Obama's foreign policy, Republicans now sense their first real opening on national security, an area that has long been considered one of the president's strengths," The Washington Post wrote.
"It was an unexpected twist that the administration seemed to grow more vulnerable following the debate between Biden, a veteran of global diplomacy and the former chairman of the Senate Foreign Relations Committee, and Paul Ryan, a relative novice whose expertise is the domestic budget," the daily said.
White House Press Secretary Jay Carney said there is no question that an attack on a diplomatic facility in Benghazi that resulted in the deaths of four Americans demonstrated that there was not adequate security to protect them.
"That is why the president and the secretary of state acted so quickly to take action to ensure that our diplomatic personnel around the world were protected and why the secretary of state, at the president's direction, created an Accountability Review Board that will assess and investigate these very issues regarding security at diplomatic facilities," he said.
"This was obviously a tragedy, and it is an incident that is under investigation both by the FBI," Carney said.
Meanwhile, Senate Homeland Security and Governmental Affairs Committee Chairman Joe Lieberman and Ranking Member Susan Collins announced they would conduct a bipartisan inquiry into the circumstances surrounding the terrorist attack on the US diplomatic mission in Benghazi that killed four Americans including Ambassador Christopher Stevens.
"We intend to examine the circumstances before, during, and after the attack, including threat awareness, US security needs for diplomatic personnel in Benghazi and Libya, and communications among the intelligence community, the State Department, the Defence Department, and the White House," Lieberman said.