WASHINGTON (AP) " Defense Secretary Jim Mattis says the U.S. has no evidence that the Syrian government has used the deadly chemical sarin on its citizens despite reports from aid groups and others in the country.
Mattis told reporters at the Pentagon on Friday that the U.S. is looking for evidence to support the claims. Syria denies it has used illegal chemicals.
Mattis says it is clear that the government of President Bashar Assad has weaponized and used chlorine gas in the Syrian civil war.
He says the U.S. is "even more concerned" about the possible use of the nerve agent sarin. Sarin is a colorless and tasteless toxin that can cause respiratory failure leading to death.