BBC News with Nick Kelly.
The United Nations Secretary General Ban Ki-moon has urged North Korea to turn down its nuclear threats. Speaking at a news conference in Madrid, Mr Ban said that nuclear threats were not a game. From Spanish capital here is Tom Burridge.
Reacting to the latest threats from North Korea towards both South Korea and the United States, the United Nations General Secretary Ban Ki-moon said the situation had become really alarming and troubling. He said that North Korea had gone too far and warned that any miscalculation could lead to a very grave outcome. Earlier a spokesman for the Russian foreign ministry said North Korea's decision to pursue nuclear status radically complicated efforts to restart the so-called six-party talks.