“I heard you had your early morning sleep disturbed many times because you had to attend the N.S.C. meetings because of us,” Mr. Kim said. “Getting up early in the morning must have become a habit for you. I will make sure that your morning sleep won’t be disturbed.”
Mr. Moon joked back: “Now I can sleep in peace.”
Mr. Moon also offered some capitalistic carrots, reminding Mr. Kim that South Korea had in years past promised huge investments to help improve the North’s road and train systems. Those agreements eventually collapsed as the North persisted in developing nuclear weapons.
Mr. Moon, a progressive leader who says he likes to see South Korea “in the driver’s seat” in pushing the peace effort forward, is trying to broker a successful summit meeting between Mr. Kim and Mr. Trump, which is expected in late May or early June.
Friday’s talks provided Mr. Moon with an opportunity to assess Mr. Kim’s intentions and personally appeal to him to give up his nuclear weapons in return for economic assistance and security guarantees, including a peace treaty with Washington and Seoul, which would help North Korea rebuild its economy.
“We are the owner of the issues on the Korean Peninsula,” Mr. Moon told Mr. Kim, according to his spokesman. “At the same time, we should go together with the rest of the world. We should take the lead and help the neighboring countries follow us.”
Mr. Kim rattled the region last year by testing long-range missiles and trading threats of nuclear war with Mr. Trump. But then Mr. Kim shifted gears, saying that he was willing to give up his nuclear weapons for the right incentives and proposing the meeting with Mr. Trump.
Last weekend, Mr. Kim announced an end to all nuclear and long-range-missile tests, saying that his country had mastered how to mount nuclear warheads on missiles and no longer needs to conduct tests. Mr. Kim said North Korea has adopted a “new strategic line” focusing on economic development.
Skeptics say Mr. Kim is trying to improve ties with South Korea to steer it from the United States and escape sanctions that are increasingly hurting the North’s economy. Indeed, many conservatives in the South fear that the North’s goal remains to be accepted as a nuclear power in return for freezing its nuclear and intercontinental-ballistic-missile programs.
Analysts have warned that once negotiations begin with the United States, North Korea could push them into a stalemate by trying to drag Washington into nuclear arms reduction talks.
To prevent that, South Korea and the United States are trying to persuade North Korea to agree to a specific timeline for complete denuclearization: as soon as possible and no later than the end of Mr. Trump’s current term, in early 2021, according to South Korean officials and analysts.
During their morning talks, Mr. Kim suggested more summit meetings with Mr. Moon, saying that he would like to visit the presidential Blue House in Seoul. He said North Korea would cooperate to make a “better world.”
But he also voiced caution, suggesting South Korea and the United States deserved blame for scuttling previous deals.
“As the expectations are high, so is the skepticism,” he said. “In the past, we had reached big agreements, but they were not implemented for more than 10 years. There are people who are skeptical that the results of today’s meeting will be properly implemented.”