U.S. special envoy for North Korea Stephen Bosworth reacts to reporter's questions at a hotel in Beijing, China, Tuesday, Nov. 23, 2010. Bosworth's Asian trip which includes South Korea and Japan,  comes after North Korea disclosed to a visiting American nuclear scientist a highly sophisticated, modern enrichment operation that had what the North says are 2,000 completed centrifuges.  (AP Photo/Alexander F. Yuan)

Photo by: Alexander F. Yuan

U.S. special envoy for North Korea Stephen Bosworth reacts to reporter's questions at a hotel in Beijing, China, Tuesday, Nov. 23, 2010. Bosworth's Asian trip which includes South Korea and Japan, comes after North Korea disclosed to a visiting American nuclear scientist a highly sophisticated, modern enrichment operation that had what the North says are 2,000 completed centrifuges. (AP Photo/Alexander F. Yuan)