TOKYO — A team of South Korean envoys delivered a letter to North Korean leader Kim Jong Un from their president on Wednesday in preparation for a planned summit they hope will maintain the momentum of their dialogue.

South Korean President Moon Jae-in is due to visit Kim in Pyongyang this month, and the envoys were hoping to set an exact date for the summit, the third between the two leaders this year, as well as firm up plans to establish a joint Korean liaison office in the North, officials said. 

They also aimed to push forward with Seoul’s plan to build closer ties with the North, which Moon considers to be the best way to build trust and persuade Pyongyang to abandon or scale back its nuclear weapons program. 

The envoys are due to fly back to Seoul on Wednesday evening, and the presidential Blue House will brief the media Thursday on the results of their mission.

Moon is playing a delicate balancing act, trying to improve relations with the North while at the same time not getting too far ahead of Washington, whose parallel peace process with Pyongyang is faltering. 

Moon phoned President Trump on Tuesday evening Korea time to brief him on the envoys’ visit and attempt to reassure him that Seoul was not letting Pyongyang off the hook by fostering closer ties.

“President Moon emphasized that now is a critical juncture for the establishment of peace on the Korean Peninsula and that such efforts go in step with complete denuclearization,” the Blue House said in a statement. 

“He stressed that improved ties between the two Koreas and tension reduction on the peninsula will contribute to complete denuclearization and establishment of permanent peace on the Korean Peninsula,” the statement added.

Trump said he sincerely hoped for a successful inter-Korean summit in September, and the two leaders agreed to look at a possible meeting on the margins of the U.N. General Assembly at the end of this month, for “in-depth consultations on strategies and how to cooperate on the peninsula issues,” the Blue House said.

Trump canceled a planned visit by Secretary of State Mike Pompeo to Pyongyang last month, citing a lack of progress in denuclearization.

At the heart of the current impasse between Washington and Pyongyang is a disagreement on which side should make the next move.

North Korea wants the United States to formally declare an end to the Korean War before it takes any concrete steps to open up or scale back its secretive nuclear program, arguing that such a step is vital to defusing tension on the Korean Peninsula and building trust. It says Trump expressed support for such an idea when he met Kim in Singapore in June.

On Tuesday, North Korea’s Foreign Ministry published a statement on its website arguing that such a declaration should be issued without delay, “as the first process, to manifest the political will to establish the lasting and stable peace regime on the Korean Peninsula.”

[North, South Koreans agree to hold Pyongyang summit in September]

Senior U.S. administration officials are believed to be very reluctant to take such a step unless they see concrete action from Pyongyang in dismantling at least part of its nuclear arsenal. 

North Korea wrote to Pompeo last month, warning that the peace process was faltering and telling him not to come to Pyongyang unless he was willing to bring further concessions, officials have said.

Before the latest setback, Moon had spoken optimistically about his planned September summit with Kim and promised that the pair would take an “audacious step” toward the signing of a peace treaty and the complete denuclearization of the Korean Peninsula. 

Last month, he also expressed hope that groundbreaking ceremonies to establish road and rail links between the two Koreas could take place before the end of the year, and he set out an ambitious vision of economic integration between the neighbors over the long term.

Koh Yu-hwan, a policy adviser at South Korea’s National Security office and professor of North Korean studies at Dongguk University, said Seoul could not simply sit on its hands because of the impasse between Pyongyang and Washington.

“If inter-Korean relations also stagnate, the diplomatic momentum could be lost,” he said in an interview. “Making headway on inter-Korean dialogue can possibly lead to progress on the denuclearization front.”

Chung Eui-yong, head of the presidential National Security Office, is leading the five-member delegation from Seoul that also includes National Intelligence Service Director Suh Hoon and Unification Vice Minister Chun Hae-sung.

The team was greeted at Pyongyang’s airport by Ri Son Gwon, chairman of North Korea’s Committee for the Peaceful Reunification, and later met Kim to deliver the letter from Moon, the Blue House announced.

Seoul’s Unification Ministry spokesman, Baik Tae-hyun, told reporters Wednesday to expect “good news” on the joint liaison office from the envoys’ visit.

Min Joo Kim reported from Seoul.

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