Boeing P-8 Poseidon

"For the 3rd time in two months, Russian pilots flew in an unsafe and unprofessional manner on May 26, while intercepting a US Navy P-8A Aircraft in the Eastern Mediterranean over international waters", it is said in a statement.

The United States and 11 NATO allies began their participation in the nine-day Breeze 19, a maritime exercise hosted by Bulgaria that included three U.S. Navy P-8A Poseidon patrol aircraft.

The exercise began Friday and is scheduled to conclude on July 21 near Varna in the Black Sea, according to a Naval news release Monday.

Russia’s air force scrambled to intercept a U.S. aircraft above the Black Sea, sending a fighter jet that came within 20 feet of its American counterpart.

A Russian fighter jet flew within a little more than 3 meters (10 feet) of a U.S. Navy surveillance aircraft, in what American officials called an unsafe intercept over the Black Sea, the Pentagon said Sept. 7, although Moscow quickly insisted the encounter was within "international rules."

Moscow and Washington have traded mutual accusations over an incident with aircraft over the Black Sea.

The Pentagon late on Wednesday blamed the Russian Air Force for what it described as a "provocation", with a Su-27 fighter jet having intercepted a US Navy surveillance aircraft over the Black Sea, flying only 3 km from the aircraft.

US surveillance aircraft and naval ships have yet to test China?s territorial claims around artificial islands built in the South China Sea, but the Pentagon warned on May 21 that could be ?the next step.?