Secretary-General Ban Ki-moon says North Korea's recent nuclear test, threats, and provocative actions have strengthened the international consensus that the reclusive communist nation will not be accepted as a nuclear weapon state.

Ban, who is South Korean, told a news conference Wednesday that the situation on the Korean peninsula remains "highly volatile" and he urged all countries in the region to step up diplomatic efforts to reduce tension and avoid "any miscalculation or misjudgment" which could lead to violence that can't be controlled.

He urged North Korea's leaders "to reverse course and work for the enhancement of their peoples' well-being."

Ban also urged the North to take South Korea's recent offer of dialogue seriously. He said he will continue efforts to facilitate talks.