China : North Korea says sanctions over the incident only caused it to bolster its nuclear deterrent . The U.N. Security Council voted unanimously to approve new measures . China calls for all leaders to step down but stands behind new U.N. sanctions . North Korea responds with a fresh statement of angry support .
NEW : North Korea says sanctions over the years only caused it to bolster its nuclear deterrent . The U.N. Security Council voted unanimously to approve new measures . China calls for all parties to calm down but stands behind new U.N. sanctions . North Korea responds with a fresh statement of angry threats .