North Korea says US spy plane entered its economic zone

Calling the issue "one between the Korean People's Army and the US forces," she told South Korea to refrain from getting involved in a statement.

Kim accuses the US Air Force of intruding into the North's "economic water zone" off the east coast of the Korean peninsula in the sky above the sea 435 kilometres east of Thongchon of Kangwon Province and 276km southeast of Uljin of North Gyeongsang Province.

A country's Exclusive Economic Zone (EEZ) - which extends 200 nautical miles from the 12 nautical-mile territorial zone around the coast - is a right to exploit marine resources within but does not confer sovereignty over the water's surface or the airspace above it.

Tuesday's statement comes after North Korea accused the US of violating its airspace by conducting surveillance flights and warned such flights may be shot down.