RICHMOND, Va. - Mitt Romney today said Vice President Joe Biden is "doubling down on denial" when he said during the debate last night that the administration was not told the U.S. consulate in Libya wanted more security ahead of the deadly attacks there last month.

"The vice president directly contradicted the sworn testimony of State Department officials," Romney said today at a campaign rally. "He's doubling down on denial."

Romney was referring to remarks Biden made during the vice presidential debate Thursday evening, in which he said, "We weren't told they wanted more security again. We did not know they wanted more security."

But earlier this week, dramatic testimony by two State Department officials on Capitol Hill revealed that they had made their reservations about the security situation in Libya known within the State Department. For example, Eric Nordstrom, the former regional security officer at the U.S. embassy in Libya, told congressional investigators that security at the U.S. diplomatic post in Benghazi, Libya, was "inappropriately low."

Romney went on to say here today that "we need to understand exactly what happened" in Libya, his second day in a row of posing harsh criticism of the administration's handling of the incident that left four Americans dead, including a U.S. ambassador. Romney said yesterday that he believed President Obama failed to grasp the "seriousness" of the attacks.

"When the vice president of the United States directly contradicts the testimony, sworn testimony, of State Department officials, American citizens have a right to know just what's going on," Romney said here today, speaking to a crowd of thousands. "And we're going to find out and this is a time to make sure we do find out."

While it was not immediately clear during the debate whether Biden was referring to the administration as a whole being unaware of the security requests, or just himself, White House press secretary Jay Carney clarified today that the vice president was referring to the White House, President Obama and himself only, according to the Associated Press.

In a written statement following Romney's remarks, Obama campaign spokeswoman Lis Smith again accused Romney of "continued politicization of the events in Libya."

"As Secretary Clinton said today, the President and his administration have been focused on getting the facts about what happened in Libya, finding the terrorists responsible, and bringing them to justice," wrote Smith. "But Mitt Romney has repeatedly rushed to launch political attacks without knowing all the facts. This is the same candidate who took multiple positions on whether we should take action in Libya in the first place."