President Obama delivered a defiant defense Monday of his administration's response to the Benghazi terror attack, calling the revived controversy over the matter a "sideshow."

The president addressed the issue during a press conference alongside British Prime Minister David Cameron, who is visiting Washington. Obama denied any suggestion that there was a cover-up, questioning recent reports that showed a State Department official trying to water down the administration's initial story-line on what happened the night of Sept. 11.

"There's no there there," Obama said. The president, further, reiterated prior arguments that he called the attack terrorism from the start, dismissing claims that the administration intentionally downplayed that element.

But Rep. Darrell Issa, R-Calif., chairman of the House Oversight and Government Reform Committee, called Obama's latest comments "revisionist history."

"The president can't have it both ways," Issa told Fox News.

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The president, with his comments, echoed remarks made by then-Secretary of State Hillary Clinton who asked during testimony in January "what difference" did the controversy over the talking points make.

Obama on Monday dismissed the questions as rooted in "political motivations."

Since Clinton's testimony, though, new details have been made public about the administration's early efforts to explain what happened in Benghazi last September. Despite claims that the White House and State Department were not heavily involved in editing the intelligence community's narrative, emails show State Department spokeswoman Victoria Nuland pushed to remove references to Al Qaeda and to the intelligence community's prior warnings about security in the region.

Based on those talking points, U.N. Ambassador Susan Rice went on five Sunday shows to claim the attack was prompted by a protest over an anti-Islam film.

Further, three State Department whistle-blowers testified last week, with one claiming he was shocked and "embarrassed" to hear Rice's comments since he knew it was a terror attack all along.

But Obama said Monday that the administration has been clear all along that officials "were not clear" at the time what was behind the attack.

"Nobody understood exactly what was taking place during the course of those first few days," Obama said.

The president also rolled out a new argument, suggesting that National Counterterrorism Center Director Matt Olsen was dispatched three days later to clear things up. He was referring to Olsen's testimony on Capitol Hill Sept. 19 in which he called the attack terrorism.

"If this was some effort on our part to try to downplay what had happened or tamp it down, that would be a pretty odd thing that three days later we end up putting out all the information," Obama said. "Who executes some sort of cover-up or effort to tamp things down for three days? So the whole thing defies logic."

But at the time, Olsen's testimony was considered major news because it ran contrary to other accounts out of the administration.

Congressional sources also told Fox News last year that Olsen was reprimanded by the White House after he testified -- though the White House denied the allegation.