CAMP DAVID, Md. (AP) -- President Barack Obama says he is not drawing a new red line on Syrian chemical weapons usage.
Obama says the U.S. is working with international partners to investigate if Syrian President Bashar Assad's government is dropping chlorine bombs.
If it is, he says, the U.S. will cooperate with international monitors and Assad's patrons, like Russia, "to put a stop to it."
Obama issued no threat Thursday, open or veiled, of military force.
He famously promised "enormous consequences" for Assad in 2012 if chemical weapons were used.
A year later, Obama decided not to order a military response. Instead, he struck a deal with Russia for Assad to relinquish his chemical arsenal.
Chlorine isn't an internationally banned chemical agent. But Obama noted its use as a weapon of war is prohibited.