A Navy video of the confrontation shows the guided-missile submarine USS Georgia moving on the surface and directed by six Navy and Coast Guard vessels as Iranian Islamic Revolutionary Guard Corps navy ships flank both sides, their machine guns uncovered and manned. American helicopters fly overhead as the American ships transit international waters in the Strait of Hormuz.
The Pentagon reported the Navy first tried to inform the Iranian Islamic Revolutionary Guard Corps naval ships of the risky movement with horn blasts, then bridge-to-bridge communication. When the unsafe maneuvers were maintained, the U.S. Coast Guard cutter Maui fired 30 warning shots in two volleys from a .50 caliber gun, the first at 300 yards and the second at 150 yards.
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"The IRGCN vessels came within 150 yards of Maui at high speed, an unnecessarily close range that put the ships and their crews in immediate danger," the U.S. Fifth Fleet said in a statement.
Two Iranian vessels that broke off and closed in on the Maui and patrol coastal ship USS Squall "increased the risk of miscalculation and collision," according to the statement.
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The IRGC navy disbanded after the second series of warning shots was fired.
“Sadly, harassment by the IRGC Navy is not a new phenomena. It is something that all our commanding officers and the crews of our vessels are trained for,” Pentagon spokesman John Kirby told reporters on Monday.
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“It’s certainly more than we’ve seen in the recent past,” he added. “It's significant.”
Kirby refused to address the Navy’s rules of engagement and under what circumstances the Navy would be permitted to sink dangerous Iranian ships.
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The United States and Iran are currently in the midst of discussions that could end U.S. sanctions in return for Tehran returning to compliance with the Joint Comprehensive Plan of Action, known commonly as the Iran nuclear deal, from which the U.S. exited in 2018 under former President Donald Trump.
Iran experts have been concerned that time is short for such negotiation as a new hard-line government is assumed to win June elections there and could further increase tensions with the U.S.
The length of time of the latest naval incident between the U.S. and Iran has not yet been made public.