CNN aired graphic videos of victims that it said were shown to select US lawmakers as part of a push to shore up support for a strike on Syria.
The broadcaster said the 13 videos were shown to members of the Senate Intelligence Committee who were told they depict victims of an August 21 chemical weapons attack in the war-torn country.
Excerpts depict convulsing children and men sprawled on the floor apparently vomiting and foaming at the mouth.
Another shows what appear to be dead bodies of dozens of Syrians, including children, lying side by side. Yet another shows a man holding the apparently lifeless body of a little boy.
The senators were told by the intelligence community that the videos had been verified, according to CNN.