A Russian fighter jet flew within 100 feet (30 meters) of the nose of a U.S. military spy plane in late April north of Japan, triggering private U.S. protests to Moscow just as East-West tensions soared over the crisis in the Ukraine, the Pentagon said.
The incident took place on April 23, when a Russian Su-27 Flanker approached the U.S. Air Force RC-135U aircraft flying on a routine mission in international airspace over the Sea of Okhotsk, officials said.
Colonel Steve Warren, a Pentagon spokesman, said Wednesday there was no radio communication between the aircraft but that the Russian jet turned as it approached the U.S. plane to expose its belly.
"Difficult to know the pilot's reasoning but the effect was that the personnel on the [American plane] were able to see that the flanker was armed," Warren told reporters Tuesday.
U.S. Defense Secretary Chuck Hagel and General Martin Dempsey, chairman of the U.S. military's Joint Chiefs of Staff, both privately expressed their concerns to Moscow, as opposed to discussing the matter publicly at the time, Warren said.
Russia's embassy in Washington did not immediately respond to a request for comment on Wednesday.