The statement from North Korea's (military) warns that it no longer considers itself bound by the terms of the 1953 ceasefire. The (immediate) cause, it says, is South Korea's decision earlier this week, to join a US-led initiative to track and search ships suspected of carrying weapons of mass (destruction).
But the angry rhetoric fits the (increasingly) hard line being taken by Pyongyang. Two days ago, it conducted a (powerful) underground nuclear test, and last month, it launched a long-range rocket over Japanese (airspace), both acts in defiance of widespread international (condemnation).
Meanwhile, South Korean news reports say that (steam) has been seen coming from a plant at the North's main nuclear (facility), a sign that it has made good on its threat to restart efforts to make weapons-grade (plutonium).
John Sudworth, BBC News, Seoul