The president of Libya said this weekend that the Sept. 11 attack on the U.S. embassy in Benghazi was carefully planned for months, contradicting a U.S. official's assurance that there was no prior knowledge of the plot.

"The way these perpetrators acted and moved, and their choosing the specific date for this so-called demonstration, this leaves us with no doubt that this was preplanned, predetermined," Mohamed Yusuf al-Magariaf, president of Libya’s General National Congress, said Sunday on CBS. He also made similar comments to NPR.

U.S. Ambassador to the United Nations Susan Rice, however, insisted that there was no foreknowledge of a plot against the embassy in Benghazi that ultimately killed four members of staff, including Ambassador J. Christopher Stevens. "We do not have information at present that leads us to conclude that this was premeditated or preplanned," she said Sunday, explaining that the attack appeared to emerge spontaneously from the protest.

Sen. John McCain (R-AZ) said as much as well, telling "This Week" that he believes the attack was premeditated and carried out with military precision. The former Republican presidential candidate also claimed President Barack Obama's strategy of "disengagement" is making American look "weak" in the region, leading radical Muslim elements to "take appropriate action" against Americans.

House Intelligence Committee Chairman Mike Rogers agreed, saying last week that the incident may even be an attack by al Qaeda. "This was not done by the Libyan government," he told CBS News. "It was done by an external group we believe has at least extremist ties, maybe al Qaeda ties, and the style and the signature of the attack clearly would be something that we have seen before and would be in line with something al Qaeda would do."

A CBS News reporter at the embassy in Benghazi said Monday morning that it appeared some complicated military hardware was used in the attacks, including mortars, feeding suspicion that whoever carried out the attack had at the very least some level of "expertise."

It's not clear whether the Obama administration will maintain the line that nobody knew anything about the attacks, but a terrorist manhunt is underway. In response to the attack, the Obama administration stepped up drone surveillance over Libya and parked two Navy destroyers loaded with cruise missiles off the coast.

This video is from CBS "This Morning," broadcast Monday, Sept. 17, 2012.

this video is from CBS "Face the Nation," broadcast Sunday, Sept. 16, 2012.

This video is from CBS "Face the Nation," broadcast Sunday, Sept. 16, 2012.