US Defense Secretary Leon Panetta has said that North Korea\'s nuclear activities are posing serious threats, not only to South Korea and the United States but also to China. Secretary Panetta said in remarks at the Institute for Defence Studies and Analyses in New Delhi, India on Thursday that South Korea, the United states and China are facing a threat of \"nuclear proliferation from an unstable North Korea , that\'s something that is as much a threat to China as it is to others in this region, and the proliferation of weapons of mass destruction,\" Panetta , who is in his first visit to India as secretary of defense to be able to address the issues in the defense arena that involve both the United States and India,said, \"And it\'s for that reason that we all have to work together in developing a cooperative relationship and developing the capabilities of these countries so that we can all confront these issues.\" Panetta meantime called on China to actively response to such threats, saying that securing the region’s stability, prosperity and peace coincides with China’s interests, Korean Broadcasting Service (KBS) reported.