US unmanned aerial surveillance vehicle enters the area of the Black Sea, Interfax reported. 

A US reconnaissance aircraft of the US Air Force Boeing RC-135V with the call sign BASTE41 took off from Souda Bay airbase in Crete, Greece on Monday morning at 7:50 am Kyiv time and headed toward the Black Sea, the source said.

"They submit applications in accordance with all the norms of international law through Ukraerorukh. They also inform the Armed Forces that they will conduct a reconnaissance flight in the waters of both the Black Sea and over Ukrainian territory. That is, all this is legal under all the norms of legislation, international law, and this was known in advance," said Ukrainian Air Forces Spokesman Dmytro Strutynsky.