Yet they still say officially they have no concrete proof of a weapons programme.
But some American analysts warn that such behavior is not necessarily proof of a weapons program.
It can't see anything else in the world today, other than the Bush-Blair original sin of launching the Iraq war, without U.N. approval or proof of Iraqi weapons of mass destruction.
But even without conclusive proof of chemical weapons use, officials said, the Pentagon has prepared a menu of options for Mr. Obama that range from airstrikes and commando raids to the enforcement of a no-fly zone over Syria.
However, the US has said that this latest intelligence does not represent proof of chemical weapons use.
Meanwhile France has said that growing proof of chemical weapons use in Syria "obliges the international community to act".
On the international front, France said growing proof of chemical weapons use in Syria "obliges the international community to act".
Also on Wednesday, French President Francois Hollande said mounting proof of chemical weapons use in Syria "obliged the international community to act", adding that any action had to be "within the framework of international law".
Newspapers in Russia warn of disaster if the West intervenes in Syria, but a commentary in China argues that proof of chemical weapons use by President Assad's troops may move Moscow to warm towards the idea.
But he added that Russia would "be ready to act in the most decisive and serious way" if there was clear proof of what weapons were used and who used them.
