A U.S. official is rejecting the claim of Bashar Assad regime's that Syrian rebels used chemical weapons.
The official says the U.S. has no evidence that either side used chemical weapons in the attack in northern Syria.
The official says the origin of the attack is still unclear.
But the official says the Organization for the Prohibition of Chemical Weapons, too, is reporting no independent information of chemical weapons use.
The official wasn't authorized to speak publicly on the matter and spoke on condition of anonymity.
The rebels deny the Syrian government claim and blame regime forces for Tuesday's missile attack on the Khan al-Assad village.
But Russia's Foreign Ministry is supporting the assertion by Assad's government, calling rebel use of an unidentified chemical agent "extremely dangerous."