The US military lost communication with a Predator drone over Syria on Tuesday and is looking into claims by state media in Damascus that the robotic aircraft was shot down, officials said.
At about 1740 GMT, "US military controllers lost contact with a US MQ-1 Predator unarmed remotely piloted aircraft operating over northwest Syria," a US defense official said in an email.
"At this time, we have no information to corroborate press reports that the aircraft was shot down. We are looking into the incident and will provide more details when available," the official said.
Syria's official SANA news agency said earlier the country's air defense forces "brought down a hostile US surveillance aircraft over north Latakia" on the coast.
If the report was accurate, it would be the first time the Syrian regime has taken out an American aircraft in its airspace since a US-led coalition fighting the Islamic State group launched bombing raids over Syrian territory in September last year.
Syria is not taking part in the coalition strikes against the jihadist group, but has so far refrained from taking action against the warplanes involved in the coalition's air war.
Damascus has said it was given prior warning before the coalition began the strikes, and Foreign Minister Walid Muallem said last year that Washington had pledged its strikes would not hit the Syrian army.