North Korea's Kim Jong Un wants a second summit with U.S. President Donald Trump soon to hasten denuclearization, but a key goal is declaring an end this year to the 1950-53 Korean War, the South's President Moon Jae-in said on Thursday.

Moon said he and Kim spent most of a three-day summit discussing how to break an impasse and restart nuclear talks between Pyongyang and Washington, which are at odds over which should come first, denuclearization or ending the war.

Kim, who recently proposed another summit with Trump after their unprecedented June talks in Singapore, said the North was willing to "permanently dismantle" key missile facilities in the presence of outside experts, and the Yongbyon main nuclear complex, if the United States took corresponding action.