Updated

The U.S. military is working on additional ways to try to halt the unending violence in Syria, but diplomacy remains the foremost option, Pentagon leaders told Congress on Thursday.

Defense Secretary Leon Panetta and Army Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, outlined the steps the United States is taking to pressure the regime of President Bashar Assad, including direct non-lethal support to the opposition such as communications equipment and emergency humanitarian assistance of $25 million. But the two made clear that unilateral military action is far from a solution.

"There is no silver bullet," Panetta told the House Armed Services Committee. "At the same time, the situation is of grave consequence to the Syrian people."

In a bipartisan response, both the chairman of the committee and the top Democrat cautioned against the Obama administration opting for military force to stop 13 months of bloodshed and violence that has devastated cities such as Homs, left thousands dead and tens of thousands displaced.

"I am not recommending U.S. military intervention, particularly in light of our grave budget situation, unless the national security threat was clear and present," said Rep. Howard "Buck" McKeon, R-Calif., the committee's chairman. "Nevertheless, these reflections lead me to wonder what the United States can do to stem the violence and hasten President Assad from power."

Rep. Adam Smith of Washington State, the panel's ranking Democrat, said the United States should support the Syrian people "but we must be extremely cautious as we discuss the potential for the use of military force."

Their comments highlighted the split in Congress on military action. Sen. John McCain of Arizona, the top Republican on the Senate Armed Services Committee and President Obama's 2008 presidential rival, has been outspoken in calling for military airstrikes against Syria. He has complained that Obama has taken too soft a stand against Assad and his brutal crackdown on his own people.

Panetta and Dempsey were updating the committee on security in Syria. Dempsey said in that so far, the military's role has been in sharing information with regional partners. But Dempsey also said the military will be ready if other options are needed.