President Moon Jae-in's top national security adviser Chung Eui-yong is heading home after his two-day trip to the United States for talks on North Korea's denuclearization.

Chung, who arrived in the United States on Friday, reportedly held talks with his counterpart John Bolton that day in Washington for two hours.

Details of the meeting have not been confirmed yet, but the two officials are believed to have shared the developments in the follow-up negotiations between Washington and Pyongyang after their summit in June in Singapore. They are also thought to have exchanged views on the direction of future discussions on the North's denuclearization.

Chung's U.S. trip came amid little progress in the follow-up talks between the United States and North Korea on how to achieve the North's denuclearization agreed in the Singapore summit.

Chung is set to arrive in Seoul on Sunday afternoon.