Fast boats from Iran's Islamic Revolutionary Guard Corps faced off against USS Essex and USS Rushmore in the Persian Gulf last week.
The Iranians warned the US ships that if they continued to fly one of their helicopters over the Iranian boats, they would open fire.
The US ships ignored the warning and downplayed the threat.
The IRGC conducted a massive military exercise in the Strait of Hormuz in August, purportedly in response to the reimposition of US sanctions on Iran.
