Senior defense officials from South Korea, the United States and other nations on Tuesday warned North Korea over its nuclear ambitions and threats, vowing an unspecified collective response to any war-like aggression by the North toward its rival. Their joint statement came after a meeting in Seoul involving US Secretary of Defense Lloyd Austin, South Korean Defense Minister Shin Won-sik and officials from 16 other countries under the US-led United Nations Command, which provided combat or medical forces in support of the South during the 1950-53 Korean War.