An Iranian Navy boat trained its gun at a passing U.S. military helicopter over the weekend, two senior U.S. military officials told NBC News.
A USS Eisenhower MH-60 Seahawk helicopter was flying ahead of the carrier group as it was sailing out of the Persian Gulf on Saturday when an Iranian Revolutionary Guards Corps boat below aimed its mounted gun at the approaching U.S. helicopter.
Neither side fired their weapons during the incident — not even warning shots, officials told NBC News.
The U.S. Navy attempted to communicate with the Iranian Navy but they didn't respond. The Eisenhower has been in the Gulf flying missions for Operations Inherent Resolve in Iraq and Syria.
A U.S. military official in the region called the action "unsafe and unprofessional."
"The air crew didn't necessarily feel threatened but it was unsafe and unprofessional," the official said.
U.S. military craft and Iranian vessels have had previous encounters.
In August a U.S. Navy ship, the USS Squall, fired several warning shots near an Iranian "fast boat" when the craft came dangerously close. That same week, four Iranian Revolutionary Guard Corps vessels near the Strait of Hormuz drawing close to the USS Nitze, a guided missile destroyer, despite repeated radio warnings.
President-elect Donald Trump vowed during a campaign rally in Florida in September that, once he is in the Oval Office, such actions would be met with swift retribution.
"With Iran, when they circle our beautiful destroyers with their little boats and they make gestures at our people, that they shouldn't be allowed to make, they will be shot out of the water," Trump promised.