"The most basic goal of our policy is that there must never be another war on the Korean Peninsula," the president said in a written interview with Indonesian newspaper Kompas.
The rare interview came ahead of Indonesian President Joko Widodo's three-day trip to Seoul. Moon and Widodo will meet Monday, one day after the Indonesian leader arrives on a state visit.
Moon noted he and North Korean leader Kim Jong-un have already agreed to denuclearize the Korean Peninsula and establish permanent peace.
"The issue is sincerely implementing the agreement reached by the leaders, and the plan is to make enough progress by the year's end so the process cannot be reversed," the South Korean president said, according to a script of his written interview released by his office Cheong Wa Dae.
Moon's remarks came as he is set to hold his third bilateral summit with the North Korean leader in Pyongyang from Sept. 18-20. Moon and Kim earlier met in the border village of Panmunjom on April 27 and May 26.
He expressed hope for a formal end to the Korean War before the year's end.
"As a practical way of building trust, it would be great if a declaration of the war that would mark the end of hostile relations on the Korean Peninsula can be made this year," Moon said.
South and North Korea technically remain at war to date as the 1950-53 war ended only with an armistice, not a peace treaty.
"As a country directly involved in issues on the Korean Peninsula, South Korea will take all necessary measures not only for the development of the South-North Korean relationship but also for the development of the North Korea-U.S. relationship and acceleration of the denuclearization process," he said. Source from the Yonhap.