The top officer in South Korea's Navy is ordering sailors to be on high alert, saying North Korea is ready to stage maritime provocations at any time.

Chief of Naval Operations Admiral Um Hyun-seong visited the Navy’s Second Fleet Command in Pyeongtaek and checked its combat readiness in the area near the Northern Limit Line(NLL), the UN-imposed sea border between the two Koreas.

Um says North Korean leader Kim Jong-un has inspecting the frontline units in the Yellow Sea, which has been a prelude to naval provocations in the past.