Joint command in South Korea elevate surveillance alert in response to N. Korean threat . But the deal foundered over verification and disclosure issues , and the North expelled international inspectors and announced plans to restart its main nuclear reactor at the Yongbyon complex . Combat readiness remains unchanged , S. Korean military spokesman says . North Korea tested nuclear weapons , missiles , threatened military action .
Joint command in South Korea elevate surveillance alert in response to N. Korean threat . Combat readiness remains unchanged , S. Korean military spokesman says . North Korea tested nuclear weapons , missiles , threatened military action .