Video appears to show Iranian helicopter's "unsafe" maneuver near U.S. warship

The Pentagon on Monday accused Iran of "unsafe and unprofessional" conduct by a naval helicopter that it said flew within about 25 yards of a U.S. Navy ship and circled it three times in the Gulf of Oman. Video published by Iranian media appeared to show the helicopter flying low and coming close to the USS Essex, an amphibious assault ship.

Pentagon press secretary John Kirby said the Iranian helicopter circled the USS Essex three times and at one point flew as low as 10 feet off the surface of the water. He said the incident on Nov. 11 had no effect on the Essex's operations.

"Without getting into specifics, the crew of the Essex took the appropriate force protection measures they felt that they needed to, and they acted in accordance with international law," Kirby said.

CBS News national security correspondent David Martin reports that previously, defense officials had said the encounter was not considered "unsafe and unprofessional" because the Iranian helicopter was not armed.

The U.S. Navy has periodically reported what it characterizes as unsafe and unprofessional encounters with Iran naval forces in the Persian Gulf and the Gulf of Oman.

Earlier this month, Iran's state-run media claimed that the Islamic Republic's military had thwarted an attempt by a U.S. vessel to "steal" a tanker full of Iranian oil as it traversed the Gulf of Oman. The claim, which was quickly refuted by U.S. officials, was the latest sign of mounting tension between the two countries amid dimming prospects for a new agreement on Iran's nuclear program.

Speaking to CBS News' Martin, U.S. Defense officials acknowledged the earlier incident, in which two U.S. Navy destroyers were sent to monitor a Vietnamese flagged tanker that was seized by Iranian Revolutionary Guards, but they said there had been no attempt to intervene or seize the cargo by the U.S. Navy.   

Tucker Reals contributed to this report.

In:
• The Pentagon