The crews of the Russian Su-24 bombers which flew near a U.S. guided missile destroyer in the Baltic Sea on Tuesday respected all safety rules, Interfax news agency quoted Russian Defence Ministry spokesman Igor Konashenkov as saying on Thursday.
The U.S. military said that the warplanes had simulated attack passes near the USS Donald Cook, with one official describing them as one of the most aggressive interactions in recent memory.
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.
"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 U.S. ship was in international waters.
The U.S. 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.
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, considers 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.
"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 of the ship, at about 100 feet 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 U.S. 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.
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U.S. Representative J. Randy Forbes, who chairs the House Armed Services subcommittee on seapower, said in a statement that "U.S. naval activity in Europe must be expanded accordingly to address the threat posed by Russia's international behavior."