The talks, which Moon said Kim requested, capped a whirlwind 24 hours of diplomatic back and forth. They allowed Moon to push for a U.S.-North Korean summit, which he sees as the best way to ease the animosity that had some fearing a war last year.

Kim may see a meeting with Trump as necessary to easing pressure from crushing sanctions and to winning security assurances in a region surrounded by enemies.

Moon told reporters that Kim said he’s willing to cooperate to end confrontation and work toward peace for the sake of the successful summit with Trump.

Moon said he told Kim that Trump has a “firm resolve” to end hostile relations with North Korea and initiate economic cooperation if Kim implements “complete denuclearization.”

“What Kim is unclear about is that he has concerns about whether his country can surely trust the United States over its promise to end hostile relations (with North Korea) and provide a security guarantee if they do denuclearization,” Moon said.

“During the South Korea-U.S. summit, President Trump said the U.S. is willing to clearly put an end to hostile relations (between the U.S. and North Korea) and help (the North) achieve economic prosperity if North Korea conducts denuclearization,” he said.

Kim, in a dispatch issued by the North’s state-run news service earlier Sunday, “expressed his fixed will” on a North Korea-U.S. summit.

During Saturday’s inter-Korean summit, the Korean leaders agreed to “positively cooperate with each other as ever to improve (North Korea)-U.S. relations and establish (a) mechanism for permanent and durable peace.”

They agreed to have their top officials meet again June 1. Moon said military generals and Red Cross officials from the Koreas will also meet separately to discuss how to ease military tensions and resume reunions of families separated by the 1950-53 Korean War.