The UN Security Council has unanimously voted in favor of a draft resolution demanding that Syria eliminate its chemical weapons.
The resolution calls for consequences if Syria fails to comply, but those will depend on the council passing another resolution.
U.S. Secretary of State John Kerry said the vote on September 27 was a victory for diplomacy.
"So tonight we are here declaring together for the first time that the use of chemical weapons, which the world long ago determined to be beyond the bounds of acceptable human behavior, are also a threat to international peace and security anywhere they might be used, anytime they might be used under any circumstances. As a community of nations, we reaffirm our responsibility to defend the defenseless, those whose lives remain at risk every day that anyone believes they can use weapons of mass destruction with impunity," Kerry declared.
U.S. President Barack Obama earlier called the draft UN resolution a "potentially huge victory for the international community" and described it as legally binding, verifiable and enforceable.
EU foreign policy chief Catherine Ashton said in a statement late on September 27 that the resolution represented "a major step towards a sustainable and unified international response to the crisis in Syria."
Ashton added the the resolution should "set a standard for the international community in responding to threats posed by weapons of mass destruction."
Russian Foreign Minister Sergei Lavrov said the Security Council was ready to back punitive measures if proven either side violated terms of the resolution.
Syria's ambassador to the United Nations, Bashar Ja'afari, said Turkey, Saudi Arabia, France, Qatar and the United States must abide by the resolution and be held accountable if they continued assisting the rebels.
UN Secretary-General Ban Ki-moon said after the vote that the big powers hoped to hold a peace conference on Syria in mid-November in Geneva.
Ja'afari said the government was "fully committed to going to Geneva" for the planned peace talks, which the rebels have also suggested they would attend.
The vote ended weeks of diplomacy between Russia and the United States.
The UN Security Council resolution was based on a deal between the two countries reached in Geneva earlier this month following an August 21 sarin nerve gas attack on a Damascus suburb that killed hundreds.
Ahead of the UN vote, the 41-member Organization for the Prohibition of Chemical Weapons approved a decision in The Hague onSeptember laying out steps to quickly verify and destroy Syria's chemical weapons stockpile.
That decision should see inspectors dispatched to Syria starting Tuesday.
Based on AP and Reuters reporting