President Moon Jae-in / Yonhap

President Moon Jae-in expressed optimism Saturday that the two Koreas will achieve "irreversible peace" and co-prosperity on the basis of his summit deal with North Korean leader Kim Jong-un a year earlier.

Celebrating the first anniversary of the signing of a set of summit agreements at the truce village of Panmunjom, Moon called it a "dramatic day."

"(The agreements in) the Panmunjom Declaration are being implemented one by one," he said in a video message for an official ceremony held on the southern side of Panmunjom.

He pointed out that South and North Korea have pulled guard posts out of the Demilitarized Zone (DMZ) and that the excavation of war remains is under way there.

Tensions have eased in fishing zones near the Yellow Sea border and a joint liaison office is in operation in Kaesong, a North Korean border town, he added.

"Preparations have been finished as well to connect (inter-Korean) railways and roads," Moon said.

His remarks came amid growing concern about stalled nuclear talks and slower-than-expected progress in inter-Korean economic cooperation. Critics of the liberal president's approach toward Pyongyang question the secretive communist nation's commitment to denuclearization, especially as its Hanoi summit with the U.S. in February abruptly concluded with no deal.

Apparently mindful of such public worries, Moon stressed, "In the face of the difficulties (we) meet at times, (we) should take a breather and find a way together."

Because it's a new path South and North Korea are traveling together, it's necessary to wait for "those who come slowly," he added.

Moon had three rounds of summits with Kim last year and he's pushing for another meeting in a bid to help revitalize the denuclearization process. (Yonhap)