The Senate vote, which ended 78-22 on Thursday evening in Washington, was always set to be an easier ride than Wednesday's vote in the lower chamber, the House of Representatives. Facing backbench opposition among war-weary Democrats, President Barack Obama had reached out to the opposition Republicans for support of the plans to offer military assistance to "moderate" rebel fighters in Syria.
"I'm pleased that Congress - a majority of Democrats and a majority of Republicans - in both the House and the Senate, have voted to support a key element of our strategy," Obama said at the White House shortly after the vote, lauding US politicians for their "speed and seriousness" dealing with the issue. "I believe our nation is strongest when the president and Congress work together," Obama also said, in a scarcely-concealed jab at the Republican-controlled House of Representatives.
The Democrat president can now sign the temporary bill - only designed to last until after November's mid-term elections - into law.
The US had long supported forces opposing President Bashar al-Assad in Syria's civil war, but had not provided direct military assistance. Now, however, the measure has been portrayed as a part of the package of measures designed to combat the self-proclaimed "Islamic State" (IS) terror group, which has taken control of parts of Syria as well as Iraq.
"IS" controls Raqqa and other Syrian territory close to the Iraqi border, mostly to the northeast. On Wednesday and Thursday, Kurdish forces currently controlling the town of Kobane (or Ayn al-Arab) on the Turkish border reported that IS fighters were besieging the settlement.
'Merci, monsieur Hollande'
Obama on Thursday said that "more than 40 countries, including Arab nations, have now offered assistance as part of this coalition" against "IS" forces. He thanked French President Francois Hollande, who on Thursday announced that France would also conduct airstrikes over Iraq - but not Syria.
"As one of our oldest and closest allies, France is a strong partner in our efforts against terrorism and we are pleased that French and American service members will once again work together on behalf of our shared security and our shared values," Obama said.
Outspoken Senator Rand Paul was among the politicians to vehemently question the military assistance for Syrian opposition fighters.
"Intervention that destabilizes the Middle East is a mistake. And yet, here we are again, wading into a civil war," Paul, the son of perennial Republican presidential hopeful Ron Paul, said.
Like his libertarian father in several races before him, Paul is considered a certainty to run in the Republican primaries as a possible presidential candidate. However, he is considered a highly unlikely final Republican choice for the 2016 presidential race.
msh/jm (AFP, AP, dpa)