Two US defense officials, speaking on condition of anonymity, claimed the incident took place when a US Navy MH-60 helicopter flew within half a mile (0.8 km) of two Iranian vessels in international waters, Reuters reported.
One of the vessels pointed a weapon at the helicopter, they added.
"The behavior by our standards is provocative and could be seen as an escalation," the officials said.
In a similar development on August 25, Pentagon officials said Iranian speedboats had “harassed” US warships in the Strait of Hormuz.
They said Iranian boats sped close to two US Navy destroyers with their weapons uncovered in the Strait of Hormuz in an “unsafe and unprofessional” encounter.
A day later, Iran’s Defense Minister Brigadier General Hossein Dehqan vowed that the Islamic Republic would confront any vessel intruding into its territorial waters.
Iran has invariably stressed that it only uses its naval might for defensive purposes and to send across the Islamic Republic’s message of peace and security to other nations.