Republican Sen. John McCain, one of the Senate's most vocal critics of how President Barack Obama's administration handled the Benghazi terror attacks in Libya, appeared to have backed away from his cover-up accusations on Tuesday when he learned that the White House had no involvement in the deletion of Al Qaeda references from the CIA’s talking points.

Instead, McCain expressed surprise and frustration at learning the Office of the Director National of Intelligence, or DNI, removed the CIA’s assessment that the terrorist group and its affiliates were responsible for the Sept. 11 assault on the U.S. consulate in Benghazi.

Four Americans were killed in the incident, which some Republicans claimed the White House wanted to dissimulate as a spontaneous event, rather than a planned terrorist attack, so as to not endanger the narrative that President Obama had made America safer by having Osama bin Laden killed.

“I participated in hours of hearings in the Senate Select Committee on Intelligence last week regarding the events in Benghazi, where senior intelligence officials were asked this very question, and all of them -- including the Director of National Intelligence himself -- told us that they did not know who made the changes,” McCain’s statement read. “Now we have to read the answers to our questions in the media. There are many other questions that remain unanswered. But this latest episode is another reason why many of us are so frustrated with, and suspicious of, the actions of this Administration when it comes to the Benghazi attack.”

In the immediate aftermath of the attack, U.S. Ambassador to the United Nations Susan Rice told the nation that the incident resulted from a spontaneous protest against an offensive, American-made anti-Islam video.

Rice’s words were different from those of the President and others in his administration who said terrorists were responsible.

Former CIA Director David Petraeus told lawmakers last week that the intelligence agency concluded that al Qaeda was responsible for the attack, but that the reference to the terror group was cut from the final talking points to be distributed to Congress, after the document had gone through interagency review.

Petraeus wasn’t aware who made the change, but the DNI claimed responsibility on Monday, when its spokesman said no agency outside its office made any “substantive changes.”

Prior to this revelation, several Republicans had gone after the Obama administration and Rice, saying there was either a cover-up, or at least incompetence.

McCain said the day the incident happened he knew that it was a terror attack.

“I know that people don’t come to spontaneous demonstrations with rockets and mortars and rocket-propelled grenades, mortars and heavy weapons,” McCain told MSNBC. “I knew that at the time.”

McCain had also threatened to block the potential nomination of Rice for Secretary of State when Hillary Clinton steps down from the post in January.

The Republican said he would “do everything in my power to block her.”

“If Sen. McCain and Sen. Graham and others want to go after someone they should go after me,” Obama said at a press conference last week, adding that he would be happy to have a discussion with them.