Washington (CNN) -- If the U.S. military is hesitant to enact a no-fly zone over Libya, the Army is capable of giving the opposition the capacity to use anti-aircraft defenses themselves, Sen. Joe Lieberman suggested Thursday.
Lieberman, I-Connecticut, raised the idea to Gen. Martin Dempsey, the chief of staff of the Army, who was testifying at a Senate Armed Services Committee hearing regarding his renomination.
Dempsey told Lieberman the Army does have the expertise to train in air defense and had done so with militaries around the world.
Lieberman has been a vocal supporter of enacting a no-fly zone above Libya and arming the opposition. The country has seen weeks of protests, with demonstrators calling for the ouster of rule Moammar Gadhafi, who has responded in some cases by having forces fire on protesters and ordering military planes to bomb opposition-held areas.
"While we're considering the no-fly zone, and I hear all the concerns about how it would be ... another alternative I'm raising is that we might provide the Libyan opposition with the capacity to defend themselves from Gadhafi's aircraft," Lieberman suggested.
U.S. military and diplomatic officials -- including Defense Secretary Robert Gates, Chairman of the Joint Chiefs of Staff Adm. Michael Mullen and Secretary of State Hillary Clinton -- have all said enacting a no-fly zone is complicated and risky, and international support for the idea is not there yet.
Speaking to Congress Wednesday, Clinton said that while all options are being considered, creating a no-fly zone is not something that will happen in the near term.
"I think we are a long way from making that decision," Clinton told the Senate Foreign Relations committee.
Gates argued Wednesday that a no-fly zone isn't a simple proposition -- a lot of equipment must be positioned, and such an operation has to begin with an attack to disable Libya's air defense. The idea should be approached with caution, he warned.
Another proponent of the no-fly zone, Sen. John McCain, R-Arizona, seemed to be trying to poke holes in that argument in questioning Gen. Dempsey at the Senate hearing, suggesting in his questions that attacking air defenses is something the United States has done before. McCain asked Dempsey if the U.S. took out air defenses in Iraq when a no-fly zone was imposed there. Dempsey said the U.S. had done so.
U.S. officials have also said that arming the opposition in Libya remains a difficult proposition because it is still unclear who will emerge as true leaders and what their motives will be.
The U.S. officials said the answer might lie with reaching out to grassroots organizations like the various tribes that make up Libyan society and disillusioned military officers.
However, Gates said Wednesday the potential capabilities of the opposition are still unclear.
"I think it remains to be seen how effectively military leaders who have defected from Gadhafi's forces can organize the opposition in the country," said Gates. "We are watching that unfold, as you are."
"We are working to understand who is legitimate, who is not, but it is premature in our opinion to recognize one group or another," Clinton said Wednesday. "I think it's important to recognize that there is a great deal of uncertainty about the motives, the opportunism, if you will, of people who are claiming to be leaders right now."
McCain seemed to take offense at Gates' comment Wednesday that there has been a lot of "loose talk" about military options, including the no-fly zone.
"May I just say personally, I don't think it's loose talk on the part of the people on the ground in Libya, nor the Arab League nor others, including the prime minister of England, that this option should be given the strongest consideration," McCain said. He continued to press the idea of a no-fly zone.
"The perception of Libyan pilots who now take off and land and attack pro-revolutionary forces might prove rather cautionary to them if they think that we will stop them and shoot them down if they carry out those missions, McCain said.
"Deterrence is always one of the options that we should have available to the national command authority," Dempsey agreed. "I will say, of course, that my own personal experience is sometimes the way our potential adversaries interpret our deterrent actions is not exactly as we've planned it. But deterrence is a valid option."
CNN's Chris Lawrence and Elise Labott contributed to this report