Pentagon Spokesman Col. Steve Warren today called it "an unsafe intercept" saying it was done in an "unprofessional and inappropriate" manner.
On May 30, two Russian Sukhoi Su-27 fighter jet conducted separate intercepts of a large U.S. RC-135 reconnaissance aircraft. According to Warren, the first of the two intercepts came dangerously close when the Russian pilot cam behind the American plane, passed underneath it and then passed it on the right hand side.
Warren said it was unclear if the jet was intentionally conducting a dangerous maneuver or if it was perhaps a general "lack of training" on behalf of the Russian pilot.
"The reason is concerns us is that these unsafe intercepts can lead to accidents and potentially tragedy or miscalculations of some sort and that is not what we want to see," Warren said.
The U.S. has filed a formal complaint with the Russians.