During the envoys’ two-day visit to Pyongyang, the North’s capital, which ended on Tuesday, the two Koreas also agreed to hold a summit meeting between Mr. Kim and President Moon Jae-in of South Korea on the countries’ border in late April, Mr. Moon’s office said in a statement.

“The North Korean side clearly stated its willingness to denuclearize,” the statement said. “It made it clear that it would have no reason to keep nuclear weapons if the military threat to the North was eliminated and its security guaranteed.”

If the statement is corroborated by North Korea, it would be the first time Mr. Kim has indicated that his government is willing to discuss giving up nuclear weapons in return for security guarantees from the United States. Until now, North Korea has said its nuclear weapons were not for bargaining away.