Russia performed an unusual mission last week, sending jets, nuclear bombers and a surveillance plane around the Korean Peninsula while the US and South Korea conducted joint military exercises.

Su-35S fighter jets, Tupolev-95MS bombers and an A-50U early warning and control aircraft flew over the Pacific Ocean, the Sea of Japan, the Yellow Sea and the East China Sea.

Seoul has accused Russian aircraft of violating its air defense identification zone, but also said their air space had not been violated. South Korea and Japan fighters eventually intercepted them.