President Barack Obama's administration fought back on Friday against Republican accusations that it covered up details of last year's deadly assault on a U.S. mission in Libya, after a news report that memos on the incident were edited to omit a CIA warning of a threat posed by al Qaeda.

The report by ABC News gave new momentum to the highly partisan flap over whether the administration tried to avoid casting the September 11, 2012, attack as terrorism at a time when the presidential election was less than two months away.

ABC released 12 versions of the administration's "talking points" on Benghazi that appeared to show how various agencies - particularly the State Department and the CIA - shaped what became the Obama's administration's initial playbook for explaining how four Americans, including U.S. Ambassador Christopher Stevens, were killed in the attack.

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The report came two days after a hearing by a House of Representatives committee in which Gregory Hicks, a former U.S. diplomat in Libya, gave a dramatic account of the night of the attack and what he described as a poorly handled response to it.

The hearing was the latest in a series of efforts by Republicans to raise questions about the administration's response to the attack by suspected Islamist militants, with an increasing focus on the role of then-Secretary of State Hillary Clinton, a possible Democratic presidential contender in 2016.

The White House has cast Republican questions as an attempt to manufacture a scandal. But the reaction to Friday's report by those in both parties suggested that Benghazi was not fading as an issue.

Obama's administration appeared to acknowledge that on Friday. White House spokesman Jay Carney held a hastily scheduled background briefing for reporters, as officials tried to defuse any political fallout from the talking-point memos.

TENSION BETWEEN AGENCIES

The memos were used to prepare Susan Rice, the U.S. ambassador to the United Nations, before she appeared on television talk shows a few days after the attack. The ABC report on the emails among the White House, State Department and intelligence agencies about the attack showed the final talking points went through a series of revisions that scrubbed them of references to previous terror warnings.

In one email exchange, the State Department's spokeswoman at the time, Victoria Nuland, objected to including the CIA's reference to intelligence about the threat from al Qaeda in Benghazi and eastern Libya.

That "could be abused by members (of Congress) to beat up the State Department for not paying attention to warnings, so why would we want to feed that either? Concerned," Nuland wrote in the email.

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A source familiar with the Benghazi memos said Nuland was concerned that the talking points went further than what she was allowed to say during her briefings and that "the CIA was attempting to exonerate itself at the State Department's expense." But the source said the deletion of references to al Qaeda and the CIA's warnings came after a White House meeting on the day before Rice appeared on five Sunday morning TV talk shows, and that Nuland was not at the meeting.

White House spokesman Carney said on Friday the changes were part of a broad effort to ensure that Rice was talking about facts and not speculation. The final talking points were approved by a CIA official the day before Rice's appearances on the talk shows, he said.

"The overriding concern of everyone involved in that circumstance is always to make sure that we are not giving to those who speak in public about these issues information that cannot be confirmed, speculation about who was responsible," Carney said. He said the White House made stylistic changes to the talking points to clarify that the Benghazi mission was not a consulate.

State Department spokesman Patrick Ventrell said critics were "cherry-picking" details from the memos but that "what was clear throughout was that extremists were involved in the attack."

A national security official with direct knowledge of the talking-point process said the State Department had objected to a draft produced by the CIA because it made it seem as if State had ignored previous intelligence warnings about the dangers in Benghazi.

'PURE, PROLONGED POLITICAL PROCESS'

Democrats have dismissed the Republican attacks as politically motivated, and they had not gained much public momentum until this week. "It's a tragedy, but I hate to see it turned into a pure, prolonged, political process that really doesn't tell us anything new about the facts," Secretary of State John Kerry, who replaced Clinton, said in a Google+ Hangout chat.

During the House hearing on Wednesday, Republicans renewed their months-old claims that the email traffic showed that the administration tried to play down the Benghazi assault because it came at the height of the U.S. presidential campaign and might have made Obama look weak on national security.

Republican House Speaker John Boehner demanded on Thursday that the administration release emails on its handling of the attack. The emails reported by ABC had been shown to members of Congress, but lawmakers and staff were not given copies, officials said.

Republican advocacy groups also entered the fray. The pro-Republican group American Crossroads released a web video that raised questions about Clinton's role in a possible "cover-up" over the White House's evolving explanations for the incident.

In the days after the attack, the administration - citing intelligence reports - essentially said it had been a demonstration that turned violent. The story soon changed to an acknowledgement that Islamist militants were behind the assault.

"Americans deserve the truth," the American Crossroads video says.

The Republican National Committee sent out portions of the ABC report in an email headlined "Obama's Bungled Benghazi Response."

Representative Elijah Cummings, a Maryland Democrat on the House of Representatives Oversight and Government Reform Committee, said the Republican accusations were an attempt to damage Clinton in case she decides to run for president in 2016.

"It is so much an effort ... to harm her before she even makes a decision and then to make sure they've got some material after she decides to run for president, assuming she does," he told MSNBC.



Additional reporting by Susan Heavey and Mark Felsenthal