WASHINGTON - North Korea's nuclear test was a 'highly provocative act' that threatened international peace and security, US Secretary of State John Kerry said on Wednesday in condemning Pyongyang's fourth nuclear test. 'This highly provocative act poses a grave threat to international peace and security and blatantly violates multiple UN Security Council resolutions,' he said in a statement. 'We do not and will not accept North Korea as a nuclear armed state, and actions such as this latest test only strengthen our resolve,' he said.