The U.N. says Secretary-General Antonio Guterres had a brief exchange with North Korea's nominal head of state and "reiterated his expectation and hope that all parties will use dialogue to achieve the denuclearization of the Korean Peninsula."

U.N. deputy spokesman Farhan Haq told reporters at U.N. headquarters that Guterres sat near 90-year-old Kim Yong Nam at a dinner Friday night, and they were also near each other during the opening ceremony of the Winter Olympics in Pyeongchang.

He said the secretary-general was also in "the same general area" as a number of other officials from Pyongyang including North Korean leader Kim Jong Un's younger sister, Kim Yo Jong, "but they were never in any personal contact with each other."