South Korea Moon says, he is pushing for progress to denuclearize North Korea

South Korea's president says he's pushing for "irrevocable" progress on efforts to denuclearize North Korea by the end of this year.

President Moon Jae-in made the comments in an interview with Indonesian newspaper Kompas published on Friday.

Moon sent a group of top officials to Pyongyang this week to help resolve a stalemate over nuclear diplomacy.

His envoys said Thursday that North Korean leader Kim Jong Un reaffirmed his commitment to a nuclear-free Korean Peninsula though he expressed frustration over outside skepticism about his sincerity.

Moon says he wants to see a declaration to end the 1950-53 Korean War being made within this year as part of trust-building measures among concerned countries.

US officials have demanded North Korea take serious, concrete disarmament steps before receiving outside concessions.