The Russian Aerospace Forces detected four reconnaissance flights near the country's border on Saturday, the Defence Ministry has said.
"Radar systems of the Russian Aerospace Forces and the Black Sea Fleet have detected and accompanied 4 flights by reconnaissance aircraft of NATO countries in the airspace over the Black Sea region over the past 24 hours", the official statement from the MoD read.
Moscow has also slammed the hostile activities of the bloc, stressing they are not contributing to stability in the Black Sea region.
"The entirely unprovoked aggressive military activity of the US and NATO countries in the Black Sea region and involvement of Black Sea states are a threat to regional security and strategic stability", the ministry's press service said in a statement.
The NATO flag is seen through barbed wire as it flies in front of the new NATO Headquarters in Brussels, Belgium May 24, 2017
© REUTERS / Christian Hartmann
Those statements come as a response to drills in the Black Sea, held by the US, Turkey, Romania, and Ukraine. The drills occurred amid escalating activity by NATO nations in the Mediterranean and near Russia's borders.
Moscow has repeatedly slammed NATO's activities in the area as a provocation to spur tensions and pursue a policy of containment of Russia.