This post has been updated.

ASHEVILLE, N.C. -- Mitt Romney called out President Obama’s campaign Thursday night for suggesting that so much attention has been focused on last month’s attack on the U.S. consulate in Libya because of politics.

At the start of remarks at an arena here, Romney told the crowd that Obama campaign aides had said that “the entire reason this has become the political topic it is because of Mitt Romney and Paul Ryan.

With that, many in the crowd gasped and booed.

"“No, President Obama, it’s an issue because this is the first time in 33 years that a United States Ambassador has been assassinated,"” Romney said. "“Mr. President, this is an issue because we were attacked successfully on the anniversary of September 11th by terrorists. This is an issue because the American people wonder why it took so long for your administration to admit that this was a terrorist attack.”"

"“This is a very serious issue,"” Romney added. “"These are very serious questions and the American people deserve serious answers and I hope they come soon."

Romney was responding to comments made earlier Thursday by Obama spokeswoman Stephanie Cutter, who said on CNN that "we are still investigating" what happened in Libya but that the attacks had become a "political topic ... ”because of Mitt Romney and Paul Ryan.”"  

Moments later, the Romney campaign responded with a written statement. But Romney'’s comments will surely amplify the issue in the coming hours, if not days.

Republicans have accused the administration of downplaying the possibility that the attack in Benghazi on Sept. 11 was a successful al-Qaeda assault. At a hearing held Wednesday by House Republicans, State Department officials acknowledged rejecting appeals for more security at its diplomatic posts in Libya in the months before the attack.

After initially saying that the assault appeared to be related to protests around an anti-Muslim film, officials are now describing it as a premeditated terror attack. State Department officials say were no protests at the compound, contrary to what other officials had said.

On CNN Wednesday, the mother of one of the Foreign Service officers killed in the attack demanded answers from the White House, saying she has gotten only "outright lies."

Cutter told Fox News later Thursday the the“administration is working "with the utmost seriousness to get to the bottom of the attacks," while "we have two people campaigning around the country accusing us of covering something up."

In his foreign policy speech Monday, Romney referenced the attacks in Libya as the “deliberate work of terrorists …who are fighting to control much of the Middle East today.” He suggested that the region was less safe because of Obama’s weak leadership, but he did not delve into the administration response. Ryan recently described the Benghazi attack as “not just an isolated incident,” but a symptom of Obama’s foreign policy weakness.