North Korea warns South Korea of military action over alleged 'violations' at sea border

North Korea warned on Sunday that it would take action against archrival South Korea for alleged violations of the de facto western maritime border.

The fresh warning came a day before South Korean, Chinese, and Japanese leaders are set to meet in Seoul for a trilateral dialogue, Seoul-based Yonhap News reported.

North Korea's supreme military leadership directed its army on Friday to take offensive action against the infringement on its sovereignty, the country's official Korean Central News Agency (KCNA) reported, citing a statement from Vice Defense Minister Kim Kang-il.

"We officially warn that we can never tolerate such continued encroachment on our maritime sovereignty and that we may exercise our self-defensive power on or under the water at any moment," Kim was quoted by the news agency as saying.

Tensions remain high along the Yellow Sea's Northern Limit Line (NLL), which serves as a de facto maritime border. North Korea has never recognized the NLL and demands that it be redrawn further south.

The waters near the NLL have been a flashpoint between the two Koreas, with three bloody naval skirmishes occurring in 1999, 2002, and 2009.

In March 2010, Pyongyang torpedoed a South Korean warship near the sea border, killing 46 sailors. In November of that year, the North bombarded Yeonpyeong, a South Korean border island, killing two civilians and two Marines.