The repeated flights by the Sukhoi SU-24 warplanes, which also flew near the ship a day earlier, were so close they created wake in the water, with 11 passes, the official said on Wednesday. The planes carried no visible weaponry, the official said.
A Russian KA-27 Helix helicopter also made seven passes around the USS Donald Cook, taking pictures. The nearest Russian territory was about 70 nautical miles away in its enclave of Kaliningrad, which sits between Lithuania and Poland.
US sanctions on Russia do not bar use of Russian rocket engines: Pentagon
"They tried to raise them (the Russian aircraft) on the radio but they did not answer," the official said, speaking on condition of anonymity, adding the US ship was in international waters.
The US military on Wednesday released photos and videos of the incidents. In one photograph, an SU-24 appears to pass at extremely low altitude over the Donald Cook's bow.
The events were reminiscent of the Cold War, when a series of close calls led to a bilateral agreement aimed at avoiding dangerous interactions at sea that was signed in 1972 by then-Secretary of the Navy John Warner and Soviet Admiral Sergei Gorshkov.
The agreement prohibited "simulated attacks against aircraft or ships, performing aerobatics over ships, or dropping hazardous objects near them." The accord can be seen here: www.state.gov/t/isn/4791.htm
Pentagon tells Russia where US commandos are based in Syria
White House spokesman Josh Earnest said, "This incident ... is entirely inconsistent with the professional norms of militaries operating in proximity to each other in international water and international airspace."
The incident came as NATO plans its biggest build-up in eastern Europe since the Cold War to counter what the alliance, and in particular the three Baltic states and Poland, consider to be a more aggressive Russia.
The Baltic states, Estonia, Latvia and Lithuania, which joined both NATO and the European Union in 2004, have asked NATO for a permanent presence of battalion-sized deployments of allied troops in each of their territories. A NATO battalion typically consists of 300 to 800 troops.
Moscow denies any intention to attack the Baltic states.
Russia raises spectre of 'world war' if nations fail to negotiate over Syria
"We cannot treat this as anything else than provocation, yet another example of aggressive intentions towards NATO, towards the United States, towards Poland," Poland's Defense Minister Antoni Macierewicz told private radio RMF.
The USS Donald Cook had just wrapped up a port visit in the Polish city of Gdynia on April 11 and proceeded out to sea with a Polish helicopter on board.
The first incident took place on April 11, when two SU-24 jets flew about 20 passes near the Donald Cook, coming within 1,000 yards (meters) of the ship, at about 100 feet (30 meters) in altitude.
That was followed by even closer passes by the SU-24s the following day and the passes by the Russian helicopter.
The U.S. defense official said the commanding officer of the Donald Cook believed that Tuesday's incident was "unsafe and unprofessional."
The US military's European Command said in a statement that "U.S. officials are using existing diplomatic channels to address the interactions, while the incidents are also being reviewed through U.S. Navy channels."
"These actions have the potential to unnecessarily escalate tensions between countries, and could result in a miscalculation or accident that could cause serious injury or death," it said.
US Representative J. Randy Forbes, who chairs the House Armed Services subcommittee on seapower, said in a statement that "US naval activity in Europe must be expanded accordingly to address the threat posed by Russia's international behavior."
RUSSIAN RESPONSE
The Russian defence ministry on Thursday said its aircraft observed all required safety measures when flying over a US warship in international waters of the Baltic Sea, dismissing criticism of unsafe conduct.
Su-24 planes were conducting test flights and "having observed the ship, turned away in observance of all safety measures," the defence ministry said, adding that the USS Donald Cook was in "operational proximity of the Russian navy's Baltic fleet base."
RUSSIAN JETS IN REPEATED 'AGGRESSIVE' PASSES OF WARSHIP: US
Russian aircraft repeatedly buzzed the USS Donald Cook this week, including an incident Tuesday in which a Russian Su-24 flew 30 feet (nine meters) above the ship in a "simulated attack profile," the US military's European Command said.
"We have deep concerns about the unsafe and unprofessional Russian flight maneuvers," EUCOM said in a statement.
"These actions have the potential to unnecessarily escalate tensions between countries and could result in a miscalculation."
Ties between Russia and the West have plunged to their lowest point since the Cold War over Moscow's annexation of the Crimean peninsula from Ukraine in 2014 and its support for separatist rebels in the east of the country.
Russia countered saying it was stunned by Washington's reaction to the fly-by incident.
Su-24 planes were conducting test flights in the area and "having observed the ship, turned away in observance of all safety measures," Russian defense ministry spokesman Igor Konashenkov said in a statement posted on the ministry's Facebook page.
"Frankly speaking, we don't understand such a sore reaction from our US colleagues," the statement added.
EUCOM released video showing warplanes zooming so close past the Cook that one sailor can be heard saying: "He is below the bridge wing," meaning the plane was flying lower than the highest point of the ship.
A senior US defense official, speaking on condition of anonymity, said: "This is more aggressive than anything we've seen in some time."
White House spokesman Josh Earnest called the overflights "entirely inconsistent with the professional norms of militaries operating in proximity to each other in international waters and international airspace."
The maneuvers began Monday while the destroyer was located about 70 nautical miles from Kaliningrad, a Russian exclave, in international waters.
Two Russian Su-24s flew 20 times past the USS Cook at a distance of less than 1,000 yards (meters) and at an altitude of about 100 feet, the official said.
Then on Tuesday, a Russian Ka-27 Helix anti-submarine helicopter flew seven times around the destroyer, taking photographs as it passed.
Shortly after, two Su-24s roared toward the ship, making 11 close-range and low-altitude passes, including one that was "so low it created wake in the water," the official said.
The plane was "wings clean," meaning it was not visibly armed, he added.
US sailors tried multiple times to hail the Russian craft on international frequencies but got no response.
"The Russian aircraft flew in a simulated attack profile and failed to respond to repeated safety advisories in both English and Russian," EUCOM said.
"USS Donald Cook's commanding officer deemed several of these maneuvers as unsafe and unprofessional."
Still, Russia defended the action.
"With the US Navy destroyer in operational proximity of the Russian navy's Baltic fleet base, the principle of its free sea navigation does not negate the principle of free air navigation of Russian planes," the Russian defence ministry statement said.
A Polish helicopter had been conducting drills on the destroyer and was refueling during one of the overflights.
"As a safety precaution, flight operations were suspended until the Su-24s departed the area," EUCOM said.
The Pentagon periodically decries the risky tactics displayed by Russian pilots.
"There have been repeated incidents over the last year where the Russian military, including Russian military aircraft, have come close enough to each other or have come close enough to other air and sea traffic to raise serious safety concerns," Earnest said.
Exactly two years ago -- on April 12, 2014 -- a Russian Su-24 made numerous close-range, low-altitude passes near the USS Donald Cook while it was in the Black Sea, in an incident the Pentagon at the time called a "provocative act."
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ