U.S. insistence that international sanctions will remain in place until North Korea fully denuclearizes is not a "realistic" position, a former top Bush Administration nuclear negotiator told NK News this week, arguing diplomats must be clearer about what Washington expects.

Speaking in an extended interview at the 19th World Knowledge Forum in Seoul, Christopher Hill, who served as head of the U.S. delegation to the Six Party Talks on North Korea's nuclear program in the 2000s, said current U.S.-DPRK talks were being undermined by a lack of clarity from both sides.