The United States is pushing the United Nations Security Council to condemn the use of chlorine as a chemical weapon in Syria, and impose unspecified measures against those who use it in the future.

A draft resolution written by the United States, obtained by The New York Times on Wednesday evening, does not specify who used chlorine as a weapon in Syria’s civil war, except to remind the government of Syria that it had agreed to destroy its chemical-weapons arsenal under a resolution adopted in September 2013.

The Organization for the Prohibition of Chemical Weapons, the global group that monitors compliance with a treaty banning these munitions, concluded in a report this year that chlorine had been used to make bombs, which witnesses said were dropped from helicopters.

That report also did not say who was to blame, although the Syrian military is the only faction in the conflict that has helicopters. Activists have previously collected video of aerial bomb attacks, in which yellow gas is seen being released.