A Russian fighter jet flew dangerously close to a US spy plane over the Black Sea on Wednesday, the Pentagon said, although Moscow quickly insisted the encounter was within “international rules.”

A Russian Su-27 Flanker jet made an unsafe, close-range intercept of a US P-8A Poseidon anti-submarine and intelligence plane conducting “routine operations” in international airspace, Pentagon spokesman Captain Jeff Davis said.

A US defence official, speaking earlier on condition of anonymity, said the Russian plane flew within 9 metres of the P-8A before closing to just 3 metres.

“These actions have the potential to unnecessarily escalate tensions, and could result in a miscalculation or accident,” Davis said.

However, Moscow said the intercept was conducted “in strict accordance with international rules” because the Americans were trying to snoop on Russian army exercises

The Russian defence ministry said in a statement that it dispatched Su-27 jets to check out US P-8 Poseidon planes as they “twice tried to get close to the Russian border over the Black Sea without their transponders turned on.”

“After the Russian fighters got close to the spy planes for visual confirmation and to determine their wing numbers, the American aircraft changed course sharply and flew away,” the statement said.

“The Russia pilots acted in strict accordance with international rules for flights.”

US Navy aircraft and ships routinely interact with Russian craft in the area, and most encounters are conducted safely.

“However, we have deep concerns when there is an unsafe manoeuvre,” Davis said.

Relations between Russia and the West are at their worst since the Cold War over Moscow’s seizure of Crimea from Ukraine and alleged fuelling of a separatist conflict in the former Soviet republic.

Washington and Moscow have reported an uptick in similar mid-air incidents between their forces as Russia flexes its muscles and the US-led NATO alliance beefs up its forces in Eastern Europe.

A similar “unsafe” intercept over the Black Sea occurred in May last year when a Russian Flanker intercepted an American RC-135 reconnaissance plane

source : gulfnews