(CNN) -- Comments by U.S. officials regarding the September 11 attack in Benghazi, Libya, that killed four Americans -- including the U.S. ambassador to the country -- have provoked controversy among some critics.
Some Republicans have accused the Obama administration of being less than forthcoming about the causes of the incident, saying it has focused on "The Innocence of Muslims," the inflammatory online video mocking the Muslim Prophet Mohammed, as the explanation for the attack.
Here's a rundown of notable statements by administration officials, publicly and in interviews with CNN:
September 12 -- President Barack Obama:
"The United States condemns in the strongest terms this outrageous and shocking attack. ... No acts of terror will ever shake the resolve of this great nation."
September 12 -- Secretary of State Hillary Clinton:
"We are working to determine the precise motivations and methods of those who carried out this assault. Some have sought to justify this vicious behavior, along with the protest that took place at our embassy in Cairo yesterday, as a response to inflammatory material posted on the Internet. America's commitment to religious tolerance goes back to the very beginning of our nation. But let me be clear -- there is no justification for this, none."
September 12 -- White House spokesman Jay Carney, in response to questions about whether the attack was planned:
"It's too early for us to make that judgment. I think -- I know that this is being investigated, and we're working with the Libyan government to investigate the incident. So I would not want to speculate on that at this time."
September 13 -- Jay Carney:
"The protests we're seeing around the region are in reaction to this movie. They are not directly in reaction to any policy of the United States or the government of the United States or the people of the United States."
September 13 -- A senior U.S. official tells CNN that the Benghazi violence was a "clearly planned attack":
"It was not an innocent mob," the official said. "The video or 9/11 made a handy excuse and could be fortuitous from their perspective, but this was a clearly planned military-type attack."
September 13 -- State Department spokeswoman Victoria Nuland:
"Well, as we said yesterday when we were on background, we are very cautious about drawing any conclusions with regard to who the perpetrators were, what their motivations were, whether it was premeditated, whether they had any external contacts, whether there was any link, until we have a chance to investigate along with the Libyans. So I know that's going to be frustrating for you, but we really want to make sure that we do this right and we don't jump to conclusions. That said, obviously, there are plenty of people around the region citing this disgusting video as something that has been motivating."
September 14 -- Jay Carney:
"We were not aware of any actionable intelligence indicating that an attack on the U.S. mission in Benghazi was planned or imminent."
September 16 -- Susan Rice, U.S. ambassador to the United Nations, on CBS' "Face the Nation":
"We do not have information at present that leads us to conclude that this was premeditated or preplanned."
September 18 -- Jay Carney:
"Our belief based on the information we have is it was the video that caused the unrest in Cairo, and the video and the unrest in Cairo that helped -- that precipitated some of the unrest in Benghazi and elsewhere. What other factors were involved is a matter of investigation."
September 19 -- Jay Carney:
"It is a simple fact that there are, in post-revolution, post-war Libya, armed groups, there are bad actors hostile to the government, hostile to the West, hostile to the United States. And as has been the case in other countries in the region, it is certainly conceivable that these groups take advantage of and exploit situations that develop, when they develop, to protest against or attack either Westerners, Americans, Western sites or American sites. ... Right now I'm saying we don't have evidence at this point that this was premeditated or preplanned to coincide on a -- to happen on a specific date or coincide with that anniversary."
September 19 -- Director of National Intelligence Matthew Olson, responding to a question by Senate Homeland Security and Governmental Affairs Chairman Joe Lieberman on whether the attack was a terrorist attack:
"They were killed in the course of a terrorist attack on our embassy. ... At this point, what I would say is that a number of different elements appear to have been involved in the attack, including individuals connected to militant groups that are prevalent in eastern Libya, particularly the Benghazi area, as well we are looking at indications that individuals involved in the attack may have had connections to al Qaeda or al Qaeda affiliates, in particular al Qaeda in the Islamic Maghreb." Olson also said U.S. officials had no "specific evidence of significant advanced planning."
September 20 -- Jay Carney:
"It is, I think, self-evident that what happened in Benghazi was a terrorist attack. Our embassy was attacked violently, and the result was four deaths of American officials."
September 20 -- President Obama at a town hall meeting organized by the Spanish-language Univsion Network, responding to a question about the possible involvement of al Qaeda:
"What we do know is that the natural protests that arose because of the outrage over the video were used as an excuse by extremists to see if they can also directly harm U.S. interests."
September 21 -- Hillary Clinton:
"What happened in Benghazi was a terrorist attack, and we will not rest until we have tracked down and brought to justice the terrorists who murdered four Americans."
September 25 -- President Obama on ABC's The View," in response interviewer Joy Behar's question, "I heard Hillary Clinton say it was an act of terrorism. Is it? What do you say?":
"We're still doing an investigation. There's no doubt that (with) the kind of weapons that were used, the ongoing assault, that it wasn't just a mob action. We don't have all the information yet, so we're still gathering it. But what's clear is that around the world there's still a lot of threats out there." Obama also said "extremist militias" were suspected to have been involved.
September 26 -- Hillary Clinton:
"What is happening inside Mali is augmented by the rising threat from violent extremism across the region. For some time, al Qaeda in the Islamic Maghreb and other groups have launched attacks and kidnappings from northern Mali into neighboring countries. Now, with a larger safe haven and increased freedom to maneuver, terrorists are seeking to extend their reach and their networks in multiple directions. And they are working with other violent extremists to undermine the democratic transitions under way in North Africa, as we tragically saw in Benghazi."
September 27 -- Secretary of Defense Leon Panetta:
"It was a terrorist attack. ... As we determined the details of what took place there, and how that attack took place, that it became clear that there were terrorists who had planned that attack."
September 27 -- A senior U.S. official tells CNN that it became clear within about a day of the Benghazi attack that it been the work of terrorists.
Separately, CNN National Security Analyst Fran Townsend reports that a law enforcement source told her that "from day one we had known clearly that this was a terrorist attack."
September 28 -- Statement by Shawn Turner, spokesman for Director of National Intelligence James Clapper:
"In the immediate aftermath, there was information that led us to assess that the attack began spontaneously following protests earlier that day at our embassy in Cairo. We provided that initial assessment to executive branch officials and members of Congress, who used that information to discuss the attack publicly and provide updates as they became available. Throughout our investigation we continued to emphasize that information gathered was preliminary and evolving. As we learned more about the attack, we revised our initial assessment to reflect new information indicating that it was a deliberate and organized terrorist attack carried out by extremists."
October 1 -- Nuland, in response to calls from Rep. Peter King, R-California, for Rice to resign because her remarks about the attack were, according to him, misleading:
"Well, let me start by saying that Secretary Clinton believes that Ambassador Rice has done a superb job. So let's just start there, and we completely reject any such calls here in this building."
October 1 -- Nuland, responding to a question about whether officials in Libya had sought additional security for diplomatic installations and personnel there:
"I think it's fair to say that we are still working through what we have in this building in terms of documentation, in terms of information about what we knew, who knew it, when they knew it, and that's part of the process that we have to go through."
October 2 -- Carney:
"I can tell you that from the moment our facility was attacked in Benghazi, the president's focus has been on securing our diplomats and facilities in Libya and around the world, and on bringing the killers to justice. At every step of the way, the administration has based its public statements on the best assessments that were provided by the intelligence community. As the intelligence community learned more information they updated Congress and the American people on it."
October 9 -- During a background briefing with reporters, a senior State Department official responding to a question about whether the attack was a spontaneous assault taking advantage of a demonstration over the movie:
"That is a question that you would have to ask, have to ask others. That was not, that was not our conclusion. I'm not saying that we had a conclusion."
The background briefing contains detailed information about the attack, including how dozens of armed men stormed the complex as Stevens and two security team members took refuge in a fortified room.
"The lethality and the number of armed people is unprecedented," one official said. "There had been no attacks like that anywhere in Libya -- Tripoli, Benghazi or anywhere -- in the time that we had been there. And so it is unprecedented, in fact, it would be very, very hard to find precedent for an attack like (it) in recent diplomatic history."
October 9 -- Clapper, during a speech in Orlando, Florida:
Upon returning from a trip to Australia, Clapper said, he was "reading the media clips about the hapless, hopeless, helpless, inept, incompetent DNI, because I acknowledged publicly that we didn't instantly have that 'God's eye, God's ear' certitude" about what had happened.
He later added, in answer to a question, "The challenge is always a tactical warning, the exact insights ahead of time that such an attack is going to take place and obviously we did not have that. This gets into the mysteries versus secrets thing. If people don't behave, emit a behavior or talk or something else ahead of time to be detected, it's going to be very hard to predict an exact attack and come up with an exact attack."