The U.S. Defense Department last week said there was evidence to suggest the Syrian government had relocated some of its chemical weapons as the regime comes under increasing pressure from military forces.
NATO Secretary-General Anders Fogh Rasmussen said Syria's chemical weapons were "a matter of great concern."
U.N. Secretary-General Ban Ki-moon, in an address to a high-ranking meeting on the prohibition of chemical weapons, expressed his appreciation for the elimination of most weapons stockpiles from the arsenals off the 188 parties to the Chemical Weapons Convention.
States like Sudan, Egypt, Israel and Syria, he added, should get in line to secure gains since the convention went into force in 1997.
"I once again emphasize the fundamental responsibility of the Syrian government to ensure the safety and security of any such stockpiles," he said. "The use of such weapons would be an outrageous crime with dire consequences."
The White House in August said a Syrian deployment of chemical weapons would trigger "enormous consequences" from the United States.