The North Korean leader on Wednesday expressed his “frustration” and “difficulties” over the international community’s doubt and “stingy evaluation” of his determination to denuclearize the Korean peninsula, a South Korean chief delegate said on Thursday.

The announcement came a day after the special presidential delegation, led by the head of the presidential National Security Office (NSO) Chung Eui-yong, made a one-day trip to Pyongyang.

Five South Korean special envoys held a meeting with North Korean leader Kim Jong Un and conveyed a letter from South Korean President Moon Jae-in.

The two sides also agreed on the date for the upcoming