A former high-ranking U.S. diplomat has held unofficial talks with a senior North Korean foreign ministry official in Switzerland.
 
The Japanese broadcaster NHK said Thursday that former U.S. principal deputy assistant secretary of state for East Asia, Evans Revere, exchanged views with deputy director general of the North Korean foreign ministry's North American affairs bureau, Choe Kang-il.
 
Both were attending a three-day international security conference on Northeast Asia that ended in Switzerland on Wednesday.
 
NHK said that details of the unofficial talks remain unknown but the latest sanctions resolution adopted by the UN Security Council in response to North Korea's nuclear test is believed to have been on the agenda.
 
The broadcaster said that the North Korean official left the venue without saying anything specific to reporters' questions.
 
Senior North Korean foreign ministry officials in charge of North American affairs have made contact with former U.S. officials several times a year on the sidelines of global conferences held in Europe, Southeast Asia and elsewhere.