Vice Admiral Kevin Donegan, the newly installed commander of the U.S. Navy’s Fifth Fleet, said that Iran’s “malign behavior” at sea has not changed since the announcement of the nuclear deal this past July, the Associated Press reported Sunday.

Donegan took command of the Dubai-based fleet in September. He told the AP that Iran’s behavior overall has him “concerned … about some of their malign behavior related to other things unrelated to the nuclear issue.”

The AP noted that, in September, a vessel sailing with a multinational force headed by the Fifth Fleet intercepted a boat, believed to be from Iran, that was transporting anti-tank missiles and other weaponry to Yemen. This occurred several months after the U.S. deployed two ships to intercept a convoy of Iranian vessels headed to Houthi rebels in the country. Donegan suggested that the incident in September was not the only recent Iranian attempt to smuggle arms to Yemen.

This past April, Iran illegally seized the Marshall Islands-flagged ship Maersk Tigris and held it for ten days. Shortly afterwards, an Iranian vessel fired on a Singapore-flagged ship in the Persian Gulf.

Donnegan remarked that “U.S. Navy ships continue to face occasional harassment from Iranian patrols,” and added that, “The behavior we’ve seen is about what we’ve come to expect. They’ll like to intercept our ships, especially the combatants, as they’re going through the straits or in other places in the Gulf. They like to show that they can shoot weapons when they’re in proximity.”

Iran has harassed and threatened the American navy in both word and action over the past year. In March, an Iranian surveillance aircraft came unusually close to a Navy helicopter from the USS Carl Vinson in the Persian Gulf. In February, the Islamic Revolutionary Guard Corps (IRGC) sunk a mock U.S. aircraft carrier during military exercises, which were broadcast on state television with the quote, “If the Americans are ready to be buried at the bottom of the waters of the Persian Gulf – so be it.” The quote was attributed to the first leader of the Islamic Republic, Ayatollah Ruhollah Khomeini. In 2014, Iran broadcast a simulation of its forces attacking Israel and the American aircraft carrier USS Abraham Lincoln on state television.

IRGC leaders have routinely directed threats at American naval forces, with senior commander Ali Fadavi saying in 2014 “that one of the IRGC navy’s operational goals is to destroy the U.S. Navy.”

Iranian naval aggression around international trade routes has been seen by experts as a challenge to American guarantees of safety for global shipping.

[Photo: U.S. Naval Forces Central Command / Flickr ]