Officials cautioned Sunday that it's too early to determine whether the United States and its allies should arm the Libyan rebels, saying the coalition is still trying to assess the influence of supposed "flickers" of Al Qaeda in the opposition.

Several lawmakers, however, made clear that it would be unacceptable for Libyan leader Muammar al-Qaddafi to stay in power, with one top official warning his weapons stockpile makes him a potential "terrorist threat."

The concerns underscored the difficult choice facing NATO leaders in terms of how far they would go to pressure Qaddafi -- does the coalition significantly boost support for the rebels risking the possibility that extremist elements exploit the situation to gain power, or does it stick to the humanitarian mission of protecting civilians risking a stalemate that leaves Qaddafi wielding control in the West?

Rep. Mike Rogers, R-Mich., chairman of the House Intelligence Committee, said the coalition has put financial pressure on the Qaddafi regime by seizing billions in assets. He said leaving Qaddafi in power is "not an option" -- but that western leaders need far more information before moving to arm the rebels.

"In most Middle East countries, there are elements of Al Qaeda," he said. "We know that they're there."

Rogers said that doesn't mean the terrorist group has a major influence among the opposition, but the United States needs to make sure its weapons aren't used against civilians, or against the United States, in the future.

"What we need to know is who they are," Rogers said in an interview on NBC's "Meet the Press." "We just need to know a lot more before we give them advanced weapons systems."

Sen. Marco Rubio, R-Fla., speaking on "Fox News Sunday," expressed similar concerns, though he said the option should not be taken off the table.

"When you talk about the Libyan rebels, well, that's a lot of different people. We need to learn about who they are and whether it would make a difference," he said.

But Sen. Lindsey Graham, R-S.C., going further than most of his colleagues, said the coalition should in fact arm the rebels when it "makes sense." Graham suggested attacking Tripoli by air while giving the rebels the equipment they need to fight the tanks on the ground.

"I think it's time to go directly after Qaddafi," Graham said on CBS' "Face the Nation." "This strategy is going to lead to a stalemate. And we should be taking the fight to Tripoli. You don't need ground troops, but we should take the aerial campaign to Tripoli to go after Qaddafi's inner circle. ... The way to end this war is to have Gadhafi's inner circle to crack. The way to get his inner circle to crack is to go after them directly."

Graham criticized the coalition for putting an end, at least for the time being, to U.S. air strikes. He said the coalition "absolutely" needs to launch direct air attacks on Qaddafi, whom he called an "international war criminal." Those U.S. air missions were expected to end Saturday, though the United States agreed to a NATO request to extend them through Monday.

The Obama administration has said Qaddafi is not a target of the military campaign, and that while pressuring Qaddafi out of power is the United States' policy goal, regime change is not the mission of the U.S. military.

This stance has frustrated lawmakers who call for a more clear-cut goal in Libya. While President Obama warns a mission of "regime change" could get the United States bogged down in the country, others warn the current policy could lead to a stalemate that likewise prevents the coalition from exiting.

The president's former national security adviser, James Jones, said Sunday that "there is no real clarity." But he said the coalition is trying to fix that, particularly by learning more about the rebels.

"I think the first thing that has to be done is to find out ... who they are," Jones said. "And so if you start from the proposition that our reason for committing our forces, as Americans or as part of NATO, was basically to avoid a massacre of innocent civilians, which probably would have happened, and now we're there, and now we have ... follow the rest of the trail to identify these people, then decide, you know, whether that's meritorious or not in terms of training, organizing, equipping."

Jones spoke on ABC's "This Week" and CNN's "State of the Union."