South Korean President Moon Jae-in (right) and North Korean leader Kim Jong Un shake hands at the truce village of Panmunjom inside the demilitarized zone separating the two Koreas on April 27, 2018 (Photo: AFP/ VNA)

South Korea held a ceremony to mark the event at the truce village of Panmunjom, which was attended by some 500 diplomats, government officials and civilians, but both Mr. Moon and Mr. Kim were absent.

In a video message broadcast at the ceremony, South Korean President Moon Jae-in expressed optimism Saturday that two Koreas will achieve "irreversible peace" and co-prosperity on the basis of his summit deal with Kim Jong Un a year earlier. Mr. Moon said the agreements in the Panmunjom Declaration are being implemented one by one.

Meanwhile, North Korea did not respond to the South's invitation for Saturday's ceremony at Panmunjom. Instead, the North's Committee for the Peaceful Reunification of the Country, which handles inter-Korean relations, urged Seoul Saturday to take "more active measures" to improve ties.