Story highlights U.S. European Command: A Russian jet flies within 50 feet of U.S. aircraft's wing tip

Russia says its pilot acted "in accordance with the international regulations on the use of airspace"

The Russian aerial maneuvers come amid rising tensions on NATO's eastern flank

Washington (CNN) A U.S. Air Force reconnaissance plane was barrel-rolled by a Russian jet over the Baltic Sea during a routine flight in international airspace, U.S. European Command said Saturday, but Russia disputed that account.

The incident Thursday occurred when a Russian jet "performed erratic and aggressive maneuvers" as it flew within 50 feet of the U.S. aircraft's wing tip, Danny Hernandez, a spokesman for U.S. European Command, said in a response to a question from CNN.

The Russian Su-27 began the barrel roll from the left side of the U.S. RC-135 and went over the top of it to end on the right side of the aircraft, European Command said.

The RC-135 aircraft was "intercepted by a Russian SU-27 in an unsafe and unprofessional manner," Hernandez said, adding that the U.S. plane never entered Russian territory.

"The unsafe and unprofessional actions of a single pilot have the potential to unnecessarily escalate tensions between countries," said Hernandez, who added the United States is protesting with the Russian government.