The USS Firebolt is seen during an exercise in the Gulf in this handout photo taken October 1, 2011. Mass Communication Specialist 2nd Class Walter M. Wayman/U.S. Navy/Handout via REUTERS.

An Iranian navy helicopter came close to a US Navy warship in the Gulf of Oman and circled it three times in an incident that ended without an impact on US operations, the Pentagon said on Monday.

Pentagon spokesman John Kirby said the Iranian helicopter came within 75 feet of the Essex warship.

“It’s dangerous because it could lead to miscalculations,” Kirby said.

He did not specify when the incident took place.