WASHINGTON — In an encounter reminiscent of the Cold War, an American reconnaissance plane crossed into Swedish airspace last month as it sought to avoid being intercepted by Russian fighters, American military officials said on Sunday.

The episode, which was disclosed only in recent days, occurred on July 18 when Russian aircraft approached an Air Force RC-135 electronic surveillance plane as it was flying in what American officials said was international airspace over the Baltic Sea.

“The aircraft commander, acting in a professional and safe manner, maneuvered the aircraft to avoid a possible encounter by Russian aircraft,” the United States European Command said in a statement.

Tensions between the West and Russia have grown over the conflict in Ukraine, and American and NATO officials have accused Russia of funneling arms to separatists in Ukraine and carrying out cross-border rocket and artillery attacks against Ukrainian government forces.