Also present were committee Chairman Robert Menendez, D-N.J., and Sen. Tim Kaine, D-Va., chairman of the Foreign Relations subcommittee on Near Eastern and South and Central Asian Affairs.

"He did specifically ask for anti-aircraft [weapons]," Sen. Bob Corker, R-Tenn., the top Republican on the panel, told Al-Monitor after the meeting.

Jarba brought his urgent appeal for military aid straight to Congress later in the afternoon, urging members of the Senate Foreign Relations Committee to authorize weapons the Obama administration is worried could fall into the hands of other, extremist forces, including terrorists groups such as the Islamic State of Iraq and al-Sham (ISIS) and Jabhat al-Nusra, who are also fighting the Syrian government.

SOC President Ahmad Jarba, in an appearance at the US Institute of Peace in Washington, said the rebels are in desperate need of weapons that can "neutralize the air force" that Assad has used to pound the cradle of the uprising, Homs, into submission, as reported by Barbara Slavin for Al-Monitor. Homs is the scene of a negotiated exit by opposition forces, a development in the three-year conflict that opposition champion John McCain, R-Ariz., labeled a "huge victory" for Assad in a hallway interview with Al-Monitor.

The leaders of the Western-backed Syrian Opposition Coalition (SOC) launched a direct appeal to Congress today for more and better weapons to defeat Syrian President Bashar al-Assad's forces.

Corker added that he would plan his next steps after he consults with Menendez. The committee last year voted 15-3 on legislation calling on the administration to provide small arms to the rebels, but it has gone nowhere in the Democratic-controlled Senate amid public reluctance for greater US involvement.

"It will be interesting when the two of us download," Corker said.

Jarba is accompanied by the new leader of the Free Syrian Army, Brig. Gen. Abdul-Ilah al-Bashir, and others on a weeklong visit aimed at shoring up public and government support for aiding the beleaguered opposition.

The opposition however ended up having to inform Congress about the kind of aid they're already receiving because of a deep disconnect between Congress and the administration that has frustrated lawmakers on both sides of the aisle.

"Candidly, it's amazing to sit with a leader of the opposition and get them to tell you more than your own government will give you," Corker told Al-Monitor. "We already sort of know because we can read you all's publications, because they like to leak things to you, but it's the same old thing with this administration: You meet with leaders of other countries and you find out what we're doing."

"We did get a rundown [during the meeting with the opposition] on the type of support the US is giving," he added. "It still seems very, very limited."

Corker isn't the only one frustrated about the lack of information about US aid.

"The only way I find out is from my sources within Syria or countries that are involved," McCain told Al-Monitor. "I think it's disgraceful that they [in the administration] don't have any communications with Congress about what they're doing. And of course what they've done until now is so little. That's also a shame."

State Department spokeswoman Jen Psaki disputed that characterization during her daily press briefing on Wednesday. She refused to answer direct questions about whether anti-aircraft weapons would be provided, however.

"We remain committed to continuing to build the capacity of the moderate opposition, including through the provision of assistance to vetted members of the moderate armed opposition," Psaki said. "As we've consistently said, we're not going to detail every element of that assistance."

That tension exploded into the open last month during a Senate hearing with Assistant Secretary of State Anne Patterson during which she suggested the administration was expanding its military aid but refused to elaborate publicly. Since then rebel leaders have given reporters in Syria a full run-down of the anti-tank weapons the US is providing, even as lawmakers outside the intelligence panels have remained in the dark.

"I think [senators] wanted to know more," said Najib Ghadbian, the coalition's US envoy, who sat in on the Senate Foreign Relations meeting. "They wanted to hear specifically about certain areas of assistance, how it would help us achieve our objectives."

The opposition has notably had to push back against the notion that it is overrun by extremists and is on its last legs following the fall of Homs. Jarba tackled those concerns head on during his Institute of Peace speech.

"We are not terrorists. We are not mercenaries. We are Syrians," he said. Jarba added that the rebel evacuation from Homs was "not the end of the world" and that the conflict would see more ups and downs.

McCain, who's scheduled to meet with Jarba on Thursday, wasn't as sanguine.

"It creates momentum for Bashar Assad for already ramped up attacks, which are continuing leading up to his 'election,'" McCain told Al-Monitor.

After briefing the Senate Foreign Relations panel, the delegation raced off to a meeting with Sen. James Inhofe, R-Okla., the top Republican on the Senate Armed Services Committee, and committee staffer Tom Goffus. They were also scheduled to meet with Sen. Bob Casey, D-Pa. — co-author with Sen. Marco Rubio, R-Fla., of legislation to provide nonlethal aid to the rebels — and Armed Services Committee Chairman Carl Levin, D-Mich., who last year joined McCain and Menendez in asking President Obama to pursue air strikes against Assad's forces.

The Syrian leader is also expected to meet with Secretary of State John Kerry on Thursday, as well as with President Obama sometime in the coming week.