China said Tuesday it had held \"frank\" talks with North Korea\'s chief nuclear negotiator, after Pyongyang announced it had invited UN inspectors to monitor a nuclear deal with the United States. A government statement said Wu Dawei, China\'s envoy for the Korean nuclear dispute, and Ri Yong-Ho had a \"frank and in-depth exchange of opinions on how to safeguard peace and stability on the Korean Peninsula\" in Beijing on Monday.