SEOUL, South Korea (AP) - North Korea vowed Tuesday to cancel the 1953 cease-fire that ended the Korean War, citing a U.S.-led push for punishing U.N. sanctions over its recent nuclear test and ongoing U.S.-South Korean joint military drills. North Korea's Korean People's Army Supreme Command warned of stronger additional countermeasures in a statement that came amid reports that Washington and North Korean ally Beijing have approved a draft of punishing sanctions for a U.N. Security Council resolution responding to North Korea's Feb. 12 nuclear test. The draft is expected to be circulated at the U.N. this week.