The U.S. Navy says it only received a radio message from Iranian naval vessels about an ongoing Iranian exercise in the Strait of Hormuz, countering Tehran claims of a tense encounter between the two fleets.

Lt. Chloe Morgan, a spokeswoman for the U.S. Navy's 5th Fleet in Bahrain, says an American warship in the Gulf of Oman heard the message on Monday.

Morgan said on Tuesday that the American vessel "continued to execute its mission and did not alter operations as a result of the radio transmission."

Iranian media had alleged its navy either "warned off" or fired "warning shots" at Saudi or American vessels during an ongoing two-day annual drill in the strait.

The U.S. Navy and Iranian forces routinely have tense encounters in the Persian Gulf.