The top Air Force general said Thursday that a no-fly zone over Libya would not be sufficient in reversing the momentum leader Muammar al-Qaddafi now has over rebel forces.

Appearing before the Senate Armed Services Committee, Chief of Staff Gen. Norton Schwartz told ranking Republican Sen. John McCain, "If the president assigns the mission to maintain a no-fly zone, clearly that would have an influence on the thinking of Libyan pilots."  

McCain then pressed the point that if a no-fly zone is imposed now it would be too little too late.

"A no-fly zone, sir, would not be sufficient," Schwartz answered.

The hearing was scheduled to address budget requests by the Defense Department, but McCain made it clear he would use the opportunity to ask about his increasing frustrations with the Obama administration's response to the month-old civil war in Libya.

"We are seeing the momentum and the success of Muammar Qaddafi and his killers massacring people while we sit idly by," McCain said. "And one of the arguments used is that we somehow can't do it, despite the fact that General Odierno just a few days ago said that it would take a very short period of time in order to impose a no-fly zone."

The U.S. is now taking a more assertive position in the United Nations, where today the Security Council is expected to vote on a no-fly zone resolution. The Obama administration has consistently said it wants Arab backing in the region as well as support from allies. France and Britain have been calling for the zone for more than a week now, but there's still convincing to do with countries like Russia and China, who is a veto-wielding council member.

McCain went on to warn Schwartz and Air Force Secretary Michael Donley that he expected "straight talk" about U.S. intentions and capabilities in dealing with the situation going forward.

Justin Fishel and Jonathan Wachtel contributed to this report