PYONGYANG -- The Democratic People's Republic of Korea (DPRK) and the Republic of Korea (ROK) have vowed to keep the momentum of inter-Korean rapprochement, the official Korean Central News Agency reported Sunday.

The pledge was made during a meeting between the ROK President Moon Jae-in and a high-ranking delegation DPRK sent to attend the opening ceremony of the 23rd Winter Olympics, the report said.

The talk, held Saturday in the presidential Blue House in Seoul, proceeded in a "sincere and cordial" atmosphere, it said.

Moon expressed gratitude to top DPRK leader Kim Jong Un for "taking a special step" by sending the high-level delegation along with Kim's personal letter and oral greetings, said the KCNA report.

But the report did not specify the details of the letter, which reportedly included a proposal to hold an inter-Korean summit in Pyongyang in near future.

Moon said he would make further efforts step by step so that the two sides could closely cooperate for common prosperity, it said.

Kim Yong Nam, president of the Presidium of the DPRK Supreme People's Assembly who was leading the delegation, expressed his confidence that with courage and decisiveness, the two sides can overcome "unimaginable difficulties" to realize reunification, the report said.

The DPRK delegation also included Kim Yo Jong, Kim Jong Un's younger sister who serves as the first vice director of the Central Committee of the ruling Workers' Party of Korea.