WASHINGTON — When the Pentagon complained about a Russian fighter plane performing a barrel roll near an Air Force reconnaissance plane in international airspace over the Baltic Sea on April 29, a quick response came from Moscow, which claimed that the American plane did not have its transponder turned on.

“The U.S. Air Force has two solutions,” the Russian Defense Ministry said in a sharp statement. “Either not to fly near our borders or to turn the transponder on for identification.” (American officials said the transponder had, indeed, been turned on.)

With that, American officials and foreign policy experts said, Russia delivered its response to President Obama’s decision this year to substantially increase the deployment of heavy weapons, armored vehicles and other equipment to NATO countries in Central and Eastern Europe. The move is meant to deter Russia from further aggression in the region.

By sharply ramping up so-called intercepts of American ships and planes in Central and Eastern Europe, Russia is demonstrating its anger over the increased American military presence in a region it considers part of its backyard, White House officials said. They called the Russian actions harassment.