The U.S. and North Korea need to formally end 76 years of hostility if the international community wants North Korean leader Kim Jong Un to stop developing nuclear weapons. That was the view expressed by Fu Ying at the Munich Security Conference on Saturday.Fu chairs the foreign-affairs committee of China's National People's Congress. She said North Korea and the U.S. have been in an extended cease-fire instead of having made peace, and the two need to enter a more normal relationship.On February 7th, North Korea launched a long-range rocket, just weeks after conducting a fourth nuclear test.So is it possible for the US and North Korea to achieve friendly relations? What will it take to bring the country back to the negotiation table? And how can the major outsiders, China and the US, cooperate on eliminating the nuclear threat from the Korean peninsula? To find out more, Brian Kopczynski and Tu Yun spoke to Yang Xiyu, senior research fellow with the China Institute of International Studies, and Rick Dunham, Co-director of the Global Business Journalism Program, Tsinghua University.