McCain explodes at US ambassador over Syria

McCain also objected to Ford's assessment that Syrian rebels are grateful for America's $385 million in humanitarian aid. Syrians he's met in refugee camps, McCain said, are “angry and bitter” at the administration's refusal to provide arms to the rebels.

The panel's chairman, Sen. Robert MenendezRobert (Bob) MenendezPoll: Menendez has 17-point lead over GOP challenger Russian attacks on America require bipartisan response from Congress Justice Dept intends to re-try Menendez in corruption case MORE (D-N.J.), on Thursday became the latest lawmaker to join calls to arm the rebels. 

Ford said the administration's policy is to support the opposition through non-lethal means. He said a negotiated political settlement that guarantees a place for the Alawite minority and regime supporters in a future Syria is the only way to end the conflict.

"If there is not a negotiated settlement," Ford said, "our sense is that regime supporters, fearing death, will fight to the death."