In this file photo from June 14, 2003, a Russian SU-24 Fencer fighter jet flies above the guided missile cruiser USS Vella Gulf during the annual maritime exercise Baltic Operations.

WASHINGTON — As tensions between the West and Russia simmer, a Russian attack plane engaged in “provocative” acts Saturday towards the destroyer USS Donald Cook in international waters, the Pentagon announced Monday.

Over the course of about 90 minutes, a Russian SU-24 fighter jet made 12 “close-range, low-altitude” passes near the Cook while the ship was in international waters in the western Black Sea near Romania, Pentagon spokesman Col. Steve Warren told reporters.

Warren did not say how close the Russian plane came to the Cook. But a U.S. Navy official, speaking on condition of anonymity, told Stars and Stripes that at one point the jet came within 1,000 yards of the vessel at an altitude of only 500 feet.

The jet did not overfly the ship, according to Warren.

Warren said the aircraft did not respond to multiple queries and warnings from the Cook. No shots were fired and the plane appeared to be unarmed, based on visual observations made by those aboard the Cook, Warren said.

Another SU-24 was also flying in the area, but not as close to the Cook as the other one, according to Warren.

“The event ended without incident,” Warren said.

Warren said the U.S. vessel was never in any serious danger, especially when faced with two seemingly unarmed aircraft.

“The Donald Cook is more than capable of defending herself against two SU-24s.”

But the Pentagon is still disturbed by the encounter.

“This provocative and unprofessional Russian action is inconsistent with international protocols and previous agreements on the professional interaction between our militaries,” Warren said.

Warren said there have been no communications between the Pentagon and the Russian ministry of defense since the incident.

The Cook arrived in the Black Sea on Thursday as the U.S. military tries to reassure allies in the region in the wake of Russia’s annexation of Crimea last month and a large Russian military buildup on Ukraine’s eastern border. The ship was conducting “routine patrolling” at the time of the incident and is now in port in Romania, according to Warren.

Warren was asked by a reporter if the Russian actions could have merely been the result of Russian pilots acting overly aggressive, of their own volition.

“I would have difficulty believing that two Russian pilots on their own would choose to take such an action,” he said.

The Pentagon views this latest incident in the context of Russia’s recent annexation of Ukraine’s Crimea region and the buildup of tens of thousands of Russian troops on the country’s eastern border.

“We’ve seen the Russians conduct themselves unprofessionally and in violation of international norms in Ukraine now for several months, and … these continued acts of provocation and unprofessionalism do nothing to help de-escalate the situation in Ukraine, which is what we’ve called on the Russians to do,” Warren said.

Gen. Philip Breedlove, the commander of U.S. and NATO forces in Europe, is scheduled to provide NATO officials with options for enhancing the alliance’s defense posture against Russia on Tuesday, including the possibility of deploying additional U.S. troops and conducting more military exercises in the region.

harper.jon@stripes.com

Twitter: @JHarperStripes

