Four American soldiers died after their vehicle was targeted with an explosive device in the countryside of the Syrian town of Markada, SANA reported, citing civil sources.
According to the report, US troops imposed a "security cordon" around the scene of explosion, and American military planes were spotted in the sky above the site.
Later on Sunday, Operation Inherent Resolve (OIR) spokesman Col. Wayne Marotto refuted the report as "false".
"The report of @CJTFOIR [International Coalition for Operation Inherent Resolve] service members KIA [killed in action] in Syria today is false. All @CJTFOIR service members have been accounted for," Marotto said on Twitter.
The vehicle that carried the American soldiers was reportedly driving the road between the cities of Hasaka and Deir Ezzor.
In its report, SANA did not specify which branch of the US military was targeted.