Pentagon leaders told Congress on Thursday that they had supported a recommendation to arm Syrian rebels promoted by the State Department and CIA but which President Barack Obama ultimately decided against.
Obama's government has limited its support to non-lethal aid for the rebels who, despite receiving weapons from countries like Qatar and Saudi Arabia, are poorly armed compared to Syrian President Bashar al-Assad's army and loyalist militias.
Syria's 22-month-long conflict has killed an estimated 60,000 people.
Senator John McCain, a Republican from Arizona, has championed greater U.S. involvement and chided the Obama administration at a hearing, asking Pentagon leaders: "How many more have to die before you recommend military action?"
He then pressed Defense Secretary Leon Panetta and General Martin Dempsey, the chairman of the U.S. military's Joint Chiefs of Staff, about whether they backed the recommendation by the State Department and CIA chiefs last year to arm the rebels.
Panetta and Dempsey said they had backed the recommendation, and later in the hearing, the defense secretary elaborated.
"Obviously there were a number of factors that were involved here that ultimately led to the president's decision to make (the aid) non-lethal," Panetta said, adding he supported Obama's decision.
The comments were the first public acknowledgement of Pentagon support to arm the rebels since the New York Times reported on February 2 about the plan developed last summer by Hillary Clinton and David Petraeus, who have since left their jobs at the State Department and CIA, respectively.
The defense chiefs' testimony also suggested that White House opposition alone may have been enough to override the position of most major U.S. foreign policy and security agencies - the State and Defense departments, and the CIA.
CONCERN ABOUT DEEPER U.S. INVOLVEMENT
The Times said that the plan to arm and train rebels was rebuffed by the White House over concerns it could draw the United States into the Syrian conflict and that the arms could fall into the wrong hands.
The questions about U.S. policy in Syria came during a hearing focusing on Libya, with Pentagon leaders defending their response to last year's deadly attack on the U.S. consulate in Benghazi.
Republican lawmakers raised questions about whether the reaction was too slow and whether Obama was not engaged enough during the incident, choosing to get updates on the crisis from staff instead of military leaders.
Panetta and Dempsey said U.S. forces could not have reached Libya in time to prevent the deaths of the U.S. ambassador and three other Americans on September 11, 2012, and assured that Obama was kept in the loop.
Panetta also stressed that it was also not the U.S. military's responsibility to be able to immediately respond anywhere in the world to a crisis. There was no intelligence about a specific plan to attack the consulate, he and Dempsey noted.
"The United States military ... is not and, frankly, should not be a 911 service capable of arriving on the scene within minutes to every possible contingency around the world," he said, referring to the 911 U.S. emergency phone number.
Panetta, who is soon retiring, also used the hearing as an opportunity to take more parting shots at Congress over its inability to reach a budget deal needed to avert automatic spending cuts that will hit the military.
Panetta warned those cuts, due to start kicking in next month, could create a "readiness crisis" for the military and urged lawmakers to strike a deal.
"I cannot imagine that people would stand by and deliberately hurt this country in terms of our national defense by letting this take place," he said.
It was likely to be Panetta's last hearing before he retires, and despite a sometimes accusatory tone from lawmakers, Republicans and Democrats praised his work as Pentagon chief and, previously, as CIA director.
The man nominated to be Panetta's successor, former Republican Senator Chuck Hagel, faces stiff Republican resistance but is expected to win Senate confirmation.