A U.S. jet shot down an Iranian drone flying in southern Syria near U.S.-backed forces, a U.S. defense official confirms to FOX News.

FOX's Lucas Tomlinson reports: 

The Pentagon says a U.S. Air Force F-15 shot down an armed Iranian drone in southern Syria early Tuesday morning after it flew too close to U.S.-backed fighters.

This marks the second time in less than a month the U.S. has shot down an Iranian-made drone. And it's the fifth time since late May the U.S. military has bombed pro-Assad forces in Syria.

Monday, the Russian defense ministry said it would target U.S. jets flying west of the Euphrates River in Syria. A day later, Australia announced it would stop flying over Syria after the U.S. downing of the Syrian jet.

It's notable Australia flies the same type of Super Hornet jet as the one that shot down that Syrian plane.

At the Pentagon, Lucas Tomlinson, FOX News.

Follow Lucas Tomlinson on Twitter: @LucasFOXNews