Washington (CNN) A Russian SU-27 conducted a “barrel roll” Friday over the top of a U.S. Air Force RC-135 which was flying a reconnaissance mission in international airspace above the Baltic Sea, the Defense Department said.

The Russian SU-27 approached alongside within 25 feet of the U.S. aircraft and then flew inverted over the top of the plane to the other side, Lt. Col. Michelle L. Baldanza, a U.S. Army spokesperson, said in a statement.

“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.

The U.S. considers this a very unsafe aerial maneuver and is expected to voice its concerns to the Russians, a U.S. defense official told CNN.

Oil Falls Below $49 A Barrel Amid China Concerns

2015-08-26t190439z451804337gf10000183572rtrmadp3venezuela-colombia In 2014, oil hit over $100 a barrel. Now, with oil dipping below $50, one of the major problems facing the market is the current excess supply, with the potential of even more coming onto the market following negotiations about lifting sanctions against oil-producing nation Iran last month. The Organization of the Petroleum Exporting Countries said there is an oversupply on the market exceeding 2 million barrels per day. The oversupply stems from high output from Saudi Arabia and Iraq.