Syria's chemical weapon stockpiles are a "great concern" but the solution to the conflict there remains political, not military, NATO head Anders Fogh Rasmussen said Monday.

NATO was monitoring the situation closely, Rasmussen told a briefing, but the position remained unchanged and there were no discussions on military options as "the right way forward as regards Syria is a political solution."

Asked if there was a 'red line' for NATO on the chemical weapons issue, Rasmussen reiterated: "We do not see a military solution in Syria."

There has been persistent speculation about Western military intervention to end the bloody conflict in Syria, as in Libya last year, but with the United States facing off against Russia and China at the UN, any such demarche looks blocked.

Washington has consistently warned Damascus against using its chemical weapons, which Syria built up from the 1970s as a strategic counter to Israel.

Earlier Monday, Syrian Foreign Minister Walid Muallem said Washington was stoking fears overs chemical weapons so as to create a scenario similar to that which led to the 2003 invasion of Iraq.

"This issue is an invention of the American administration," Muallem told Beirut-based Al-Mayadeen TV in excerpts to be broadcast in full later Monday.

"These chemical weapons in Syria, if they exist -- and I emphasise if -- how is it possible that we would use them against our own people? It's a joke," he said.

A US-led coalition invaded Iraq in 2003, accusing its president Saddam Hussein of possessing weapons of mass destruction but none were ever found.

Damascus acknowledged for the first time in late July that it possessed chemical weapons and threatened to use them if attacked by outside countries but never against its own people.

US Defense Secretary Leon Panetta said on Friday that Damascus had moved some chemical weapons to safeguard the material but that the main storage sites for its arsenal remained secure.