Libyan President Mohamed Yousef El-Magariaf said he is convinced a Tuesday attack on the U.S. consulate in Benghazi that left four Americans dead was premeditated, but the U.S. ambassador to the United Nations said Sunday that the protests near the consulate began spontaneously, but were later hijacked by armed extremists.

"The way these perpetrators acted, and moved ... and they’re choosing the specific date for this so-called demonstration, I think we have no, this leaves us with no doubt that this was preplanned, determined…predetermined," Magariaf said in an interview on CBS's "Face The Nation" set to air later Sunday morning.

The attack claimed the life of U.S. Ambassador to Libya J. Christopher Stevens and three other Americans. The FBI has is conducting an investigation into the events surrounding the incident.

"What this began as was a spontaneous, not a premeditated response to what happened in Cairo," Susan Rice, the U.S. Ambassador to the United Nations, said in an interview on ABC's "This Week With George Stephanopoulos."

Hours before the attack in Benghazi, protesters moved against the U.S. Embassy in Cairo, Egypt, scaling the embassy walls and entering its outer grounds. The protests were an apparent reaction to an anti-Islam film linked to a California man.

"We believe that folks in Benghazi, a small number of people came to the embassy to -- or to the consulate, rather, to replicate the sort of challenge that was posed in Cairo," Rice said.  "And then as that unfolded, it seems to have been hijacked, let us say, by some individual clusters of extremists who came with heavier weapons."

"We do not have information at present that leads us to conclude that this was premeditated or preplanned," Rice said on CBS.

Sen. John McCain (R-Ariz.), also speaking on CBS, appeared to disagree with the suggestion that the attack was spontaneous. "Most people don't bring rocket propelled grenades and heavy weapons to a demonstration. That was an act of terror, and for anyone to disagree with that fundamental fact, I think is really ignoring of the facts," said McCain, the ranking Republican on the Senate Armed Services Committee.

House Intelligence Committee Mike Rogers (Mich.) echoed a similar sentiment on "Fox News Sunday." He said: "I'm just suspect that they could come to that conclusion so assuredly -- that it was a spontaneous effort, given the coordination of it."

When asked whether it is safe for FBI investigators from the United States to come into the country, or if he is advising them to stay away for a while, Magariaf responded: "Maybe it is better for them to stay for a little while, for a little while. But until we ... we do what we have to do ourselves. But again when we need for their presence to help in further investigation ... and any hasty action I think is not welcome," Magariaf said.

Updated at 11:17 a.m.