The Senate Foreign Relations Committee voted 10-7 in favor of a compromise resolution that sets a 60-day limit on any engagement in Syria and bars the use of US troops on the ground for combat operations.
The compromise is more limited than President Barack Obama's original proposal but meets the administration's goal of punishing Syria for what the U.S. government says is the use of chemical weapons on Syrian civilians, killing more than 1,400 people.
The authorization still faces significant resistance in Congress, where many lawmakers fear it could lead to a prolonged U.S. military involvement in Syria's civil war and spark an escalation of regional violence.
The full Senate is expected to vote on the resolution next week. The House of Representatives also must approve the measure.
Obama and administration officials have pushed Congress to act quickly, saying U.S. national security and international credibility is at stake in the decision whether to use force in Syria to punish President Bashar al-Assad's government for chemical weapons use.
"If we don't take a stand here today, I guarantee you, we are more likely to face far greater risks to our security and a far greater likelihood of conflict that demands our action in the future," Secretary of State John Kerry told the House Foreign Affairs Committee at a separate meeting on Wednesday.
"Assad will read our silence, our unwillingness to act, as a signal that he can use his weapons with impunity," Kerry said.
The committee vote came after the two panel leaders - Democratic Chairman Robert Menendez and senior Republican Bob Corker - crafted a compromise to meet concerns from some lawmakers that Obama's resolution was too open-ended.
Republican Senator John McCain of Arizona had objected to the more narrow wording. But the committee adopted amendments proposed by McCain with policy goals of degrading Assad's ability to use chemical weapons, increasing support for rebel forces and reversing battlefield momentum to create conditions for Assad's removal.
Many lawmakers have said they are worried the resolution could lead to U.S. ground troops, or "boots on the ground," in Syria - which administration officials said would not happen.
"It's very clear on the House side there is no support for boots on the ground," House Foreign Affairs Committee Chairman Ed Royce told Kerry at Wednesday's hearing, which also featured testimony from Defense Secretary Chuck Hagel and General Martin Dempsey, chairman of the Joint Chiefs of Staff.
Kerry answered flatly, "There will be no boots on the ground. The president has said it again and again."