A Russian Su-27 jet flew dangerously close to a U.S. Air Force RC-135 aircraft over the Baltic Sea on Friday, military officials said.
The Russian plane flew within 25 feet of the RC-135's fuselage, conducting a barrel roll over the U.S. plane.
Lt. Col Michelle Baldanza, a Defense Department Spokesperson said that, "on April 29, 2016, a U.S. Air Force RC-135 aircraft flying a routine route in international airspace over the Baltic Sea was intercepted by a Russian SU-27 in an unsafe and unprofessional manner."
She added that the Russian plane "performed erratic and aggressive maneuvers" and that "the SU-27 intercepted the U.S. aircraft flying a routine route at high rate of speed from the side then proceeded to perform an aggressive maneuver that posed a threat to the safety of the U.S. aircrew in the RC-135."
Baldanza said that the U.S. aircraft was operating in international airspace and "at no time crossed into Russian territory."
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"This unsafe and unprofessional air intercept has the potential to cause serious harm and injury to all aircrews involved. More importantly, the unsafe and unprofessional actions of a single pilot have the potential to unnecessarily escalate tensions between countries," she added.
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This comes just a few weeks after Russian aircraft flew dangerously close to the USS Donald Cook and another RC-135 in the same area.
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Foreign policy experts say Russia has increasingly engaged in brinksmanship as warplanes buzzing near or in the airspace of other nations. In October, Russian warplanes flew near the USS Ronald Reagan aircraft carrier in the Sea of Japan and the Navy was forced to send U.S. fighter jets in response.
"This is an escalating trend," Keir Giles, an associate fellow at the London-based Chatham House think tank, told NBC News earlier this month of the USS Donald Cook incident. "There have been lots of provocative actions by Russian aircraft, but they have been getting more provocative, more dangerous, and more in breach of safety regulations at sea."