A Russian Sukhoi Su-27 fighter jet has reportedly intercepted a US Navy P-8 surveillance plane over the Black Sea, a development that could increase tensions between the countries.
The Russian aircraft came within ten feet of the US plane that was conducting a routine patrol in international airspace.
It made four intercepts and of which lasted for more than 19 minutes.
Russian Defense Ministry Spokesman major general Igor Konashenkov was reported by The Associated Press as saying that the Su-27 was sent to intercept the US spy plane that approached the Russia's southern border twice and whose transponder was switched off.
However, a senior US defence official said that the Poseidon's transponders were turned on throughout the flight.
US Department of Defense spokesman Jeff Davis was quoted by the news agency as saying: "However, we have concerns when there is an unsafe maneuver like this.
"These actions have the potential to unnecessarily escalate tensions, and could result in a miscalculation or accident."
The latest interception follows a series of similar incidents involving Russian and US aircraft. Earlier this year, Russian jets flew over the USS Donald Cook in the Baltic Sea.