On Friday, Mr. Kim and Mr. Moon signed a joint declaration recognizing “a nuclear-free Korean Peninsula” and “complete denuclearization” as a common goal of the two Koreas. But during the summit events, some of which were broadcast live around the world, Mr. Kim never publicly renounced his nuclear weapons.

Even in the additional details released on Sunday by South Korean officials, Mr. Kim appeared to hedge his bet, indicating that denuclearizing his country could be a long process that required multiple rounds of negotiations and steps to build trust. But he laid out a vague idea of what his impoverished country would demand in return for giving up its nuclear weapons.

”If we meet often and build trust with the United States and if an end to the war and nonaggression are promised, why would we live in difficulty with nuclear weapons?” Mr. Kim was quoted as saying by South Korean officials.