Updated

A top Obama campaign official on Thursday blamed Mitt Romney and Paul Ryan for the political debate over the consulate attack in Libya, saying the Republican candidates' complaints are the "entire reason" for the controversy -- a claim that was immediately rejected by the Romney campaign.

The Romney and Ryan campaign, after an initial burst of criticism, actually stayed relatively quiet on the deadly Libya attack for days after the violence, even as members of Congress voiced concern that the administration was misleading the public on its cause.

But Obama deputy campaign manager Stephanie Cutter claimed Thursday, hours before Ryan and Vice President Biden were set to meet for their only debate, that the GOP ticket was the reason.

"Paul Ryan has politicized and made it a political circus all over this country over the terrible tragedy that happened in Libya," she said.

Speaking on CNN, she added: "In terms of the politicization of this ... the entire reason that this has become the political topic it is, is because of Mitt Romney and Paul Ryan. It's a big part of their stump speech. And it's reckless and irresponsible what they're doing."

Cutter stood by those comments Thursday evening on Fox News.

"I was asked why it became such a political circus. And who was the first person to respond to the Libya attacks? It was Mitt Romney," she said on "Special Report With Bret Baier." "And he's continued to attack the president on the response to Libya."

But Romney objected to her claims.

"It's its an issue because this is the firs time in 36 years that an ambassador has been assassinated," Romney said in a TV interview. "This is an issue because we were attacked by terrorists on Sept 11. This is an issue because Americans wonder why it took so long for you and your administration to admit it was a terrorist attack.

"This is a very serious issue and they deserve serious answer, and I hope they come soon."

Ambassador Chris Stevens and three other Americans were killed in the attack.

Members of Congress have been leading the charge on questioning the administration over Libya. The Republican-controlled House Oversight and Government Reform Committee held a tense hearing on Wednesday to demand answers from the State Department on why the administration initially claimed the attack grew out of a protest, and why certain security requests were not granted.

Romney and Ryan have in recent weeks stepped up their criticism of the president over Libya. In an interview with Fox News last week, Romney called the attack a "tragic failure" of security and said the administration's explanations have been "misleading."

But it took until late September for either Republican running mate to seriously challenge the administration over the consulate strike. On the night of the attack, Romney had criticized the U.S. Embassy in Cairo over its handling of a separate protest in Egypt. But after being hammered by Democrats for that criticism in the immediate aftermath of the Libya tragedy, Romney softened his talking points on the matter for days.