"Every capability that we deploy, every ship that deploys in harm’s way has an inherent right to self-defence. What that means is if we see a hostile act, a hostile intent, we have the right to respond up to including lethal force," Vice Chairman of the Joint Chiefs of Staff John Hyten told reporters. "But nobody should doubt that the commanders have the authority right now to respond to any hostile act or hostile intent."
Hyten praised Trump’s message to Iran, saying, "That’s perfect. We know how to translate that into the rules of engagement."
However, Hyten refused to elaborate on the rules of engagement and said they mean that a commander cannot let an enemy vessel "get in a position where it can threaten your ship."
"What he was emphasizing is that all of our ships retain the right of self-defence," Norquist said.
The apparent warning comes one week after Iranian fast boats harassed US Navy ships in the Persian Gulf.
Earlier in the day, Trump said via Twitter that he has directed the US Navy to attack and destroy any Iranian gunboats that approach and intimidate US warships at sea.