Secretary of State Hillary Clinton suggested the deadly consulate attack in Libya involved the Al Qaeda affiliate in North Africa, going further than any other Obama administration official in acknowledging the assault was the work of hardened terrorists.

Clinton was speaking Wednesday to foreign leaders gathered at a meeting convened by U.N. Secretary General Ban Ki-Moon to address the threat of extremism in the region.

“Now with a larger safe haven and increased freedom to maneuver, terrorists are seeking to extend their reach and their networks in multiple directions,” Clinton told the group, according to a New York Times report. “And they are working with other violent extremists to undermine the democratic transitions under way in North Africa, as we tragically saw in Benghazi.”

It wasn't the first time Clinton had referred to the attack on the U.S. Consulate in Benghazi, Libya, as a terrorist attack. But her reference to the group Al Qaeda in the Islamic Maghreb was notable, especially as President Obama still has yet to publicly refer to the attack as terrorism.

Republicans have pounced on the administration's shifting explanation for the Sept. 11 attack, which left U.S. Ambassador Christopher Stevens and three other Americans dead. Administration officials initially described it as "spontaneous" violence, possibly related to protests against an anti-Islam film produced in the U.S., but the administration has gradually walked that explanation back while acknowledging the attack was an act of terror.

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The White House said Wednesday that Obama, too, considers the deadly assault an act of terror. Press Secretary Jay Carney said it is "certainly the case that it is our view as an administration, and the president's view, that it was a terrorist attack."

Carney's comments came after Mitt Romney accused Obama of failing to "level with the American people" about the nature of the attack.

Obama has declined several chances to call the incident a terrorist attack. He said last week that extremists used an anti-Islam video as an excuse to assault U.S. interests, and in an interview this week on ABC's "The View," he would only say that it clearly "wasn't just a mob action."

On Capitol Hill, eight Republicans who head House committees sent a letter to Obama saying they were disturbed by statements from administration officials suggesting that the attack was a protest gone wrong rather than a terrorist attack. They said they would be willing to return to Washington from Congress' nearly two-month recess if the administration scheduled another briefing on Libya.

Clinton and senior Pentagon and intelligence officials briefed members of the House and Senate last Thursday on Libya.

Republican Sens. John McCain of Arizona and Lindsey Graham of South Carolina called the continued threat of terrorism "an inconvenient truth" for Obama, given his re-election campaign's efforts to tout the progress made against Al Qaeda.

“But it is not too much to ask why the president and his administration have taken so long to state what has appeared obvious for a long time about what really happened in Benghazi," the senators said in a joint statement. "This is just one more example of this president's failure to lead in the Middle East and how that failure has threatened America's national security interests. Now is not the time to lead from behind.”

The Associated Press contributed to this report.