The Obama campaign was facing intense criticism from conservatives on Thursday after a senior official said the deadly attack on the US consulate in Benghazi was only an issue because Mitt Romney was exploiting the deaths for political gain.

The president's deputy campaign manager, Stephanie Cutter, told CNN attention was being paid to the killing of the US ambassador to Libya, Chris Stevens, and three other Americans on September 11 because the Republican presidential candidate and his running mate, Paul Ryan, are seeking electoral advantage.

"The entire reason that this has become the, you know, political topic it is is because of Mitt Romney and Paul Ryan," said Cutter. "It's a big part of their stump speech, and it's reckless and irresponsible, what they're doing."

Cutter added that Ryan "made a political circus all over this country of the terrible tragedy that happened in Libya."

Her remarks drew an immediate rejection from the Romney campaign, which called them "outrageous".

The Romney campaign press secretary, Andrea Saul, dismissed Cutter's charge.

"The reason it is an issue is because, for the first time since 1979, an American ambassador was assassinated – and President Obama's foreign policy strategy of 'leading from behind' is failing," she said.

"This administration has continually misled the American public about what happened in Benghazi and, rather than be truthful about the sequence of events, has instead skirted responsibility and dodged questions. The American people deserve straight answers about this tragic event and a president who can provide leadership, not excuses."

Other Republicans said the administration has questions to answer not only as to how the attack occurred but why it initially claimed that the assault was a backlash against an anti-Muslim video before calling it a terrorist attack.

The Obama campaign defended Cutter's remarks by saying that while Romney and Ryan have "turned a national tragedy into a political circus, the president has been focused on getting the facts, finding the terrorists responsible, and bringing them to justice".

Immediately after the Benghazi attack, Romney criticised Obama for sending "mixed signals" to foes in the Middle East. Since then Romney has accused the president of "keeping the facts" about the killings from the American people and chided him for not being quick enough to call the assault on the consulate a "terrorist attack".

Ryan has been even more strident in repeatedly portraying the Libya attack as evidence of the failure of Obama's foreign policy.

"If you turn on the TV today you can see that the Obama foreign policy is unravelling before our eyes," Ryan said in Iowa earlier this month. "It's not just an isolated incident where we lost four Americans in Libya. That's a tragedy. But it's part of a bigger story of the unravelling of this agenda all over the world. We've distanced our ally Israel, we are not advancing our interests in the Middle East, and the president is promising that we're going to have these devastating cuts to our national defence."

Cutter's remarks followed Wednesday's clearly partisan Congressional hearing into the killings in Benghazi. Democrats on the House of Representatives oversight committee accused the Republican chairman, Darrel Issa, of politicising them by attempting to suggest that the White House had attempted to cover up an al-Qaida attack by initially claiming the attack was prompted by popular outrage against an anti-Muslim video.

However, testimony from two former heads of US diplomatic security in Libya was damaging to the Obama administration after they told the committee that requests for additional agents to protect US officials and premises in the face of a growing threat from armed militias were rejected by the state department before the attack on Benghazi.

Cutter denied Republican assertions of a cover-up. "The administration has been open and honest from day one about the Benghazi attack," she said "As more information has become available, they've made that information available to the American people and to members of Congress. But, you know, when a crisis occurs, when an attack occurs, that information is gathered and over time it's more clear what happened." © Guardian News and Media 2012