U.S. special envoy Stephen Bosworth (2nd R) is seen at the Sunan Airport before leaving for South Korea, in Pyongyang, December 10, 2009. Bosworth, the first envoy sent by U.S. President Barack Obama to North Korea, ended a three-day trip on Thursday where he said he had a 'useful meeting' aimed at bringing Pyongyang back to nuclear disarmament discussions. REUTERS/Xinhua/Yao Ximeng (NORTH KOREA POLITICS) NO SALES. NO ARCHIVES. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. CHINA OUT. NO COMMERCIAL OR EDITORIAL SALES IN CHINA. YES