Moon's first exclusive interview with a Japanese newspaper came ahead of his trip to Tokyo on Wednesday for a three-way summit with Japanese Prime Minister Shinzo Abe and Chinese Prime Minister Li Keqiang.

The South Korean leader noted the importance Japan places on the issue of Japanese nationals abducted by Pyongyang and said he has raised the issue with North Korea at nearly every opportunity, including his recent summit with North Korean leader Kim Jong-un.

"I have also discussed the North Korea-Japan relationship with Chairman Kim Jong-un," he said, referring to the North Korean leader by his official title as the head of the state affairs council. "I told Chairman Kim that Prime Minister Abe is willing to normalize the North-Japan relationship based on the spirit of clearing the problems of the past, and he said he is willing to talk with Japan at any time."

Moon urged the two countries to start discussing the issue, saying only dialogue can help narrow differences.

"When we look back, pessimistic views had outnumbered optimistic views about a change in North Korea's behavior, including the North Korean nuclear issue. But our continued efforts for dialogue made a small breakthrough at the PyeongChang Winter Olympic Games and at the South-North Korea summit. North Korea agreed to compete denuclearization and the establishment of permanent peace," the president said.

The historic Moon-Kim summit, held April 27, followed the rapprochement between the divided Koreas prompted by the North's participation in the Winter Olympics held earlier this year in South Korea.

Moon said the North Korean leader clearly understood what he and his country needed to do to ensure their safety and that he is willing to take such measures.

"Chairman Kim clearly understands what the international community wants. I plan to do all I can to help strengthen the trust between the North and the US so their negotiations may go well, and I will closely cooperate with key nations of the international community, including Japan, in that process," he said.

The South Korean president also expressed hope for improved relations between his country and Japan but said that may require Japan's sincere apology over its past wrongdoings.

"South Korea and Japan have more than 2,000 years of shared history. There have been times when exchanges and cooperation flourished and times that were dark and unfortunate," Moon said.

"I have consistently called for efforts to wisely overcome history issues between the two countries while pushing for future-oriented cooperation on the other hand," he said.

History issues between the two countries mostly stem from Japan's 1910-45 colonial rule of Korea, during which hundreds of thousands, if not millions, of Korean people are believed to have been put into forced labor or sexual slavery.

The ousted former South Korean leader, Park Geun-hye, reached a controversial and widely disputed deal with Japan in 2015 to settle the sexual slavery issue once and for all in exchange for 1 billion Japanese yen ($9.2 million).

The Moon Jae-in administration has declared the agreement flawed and ineffective, also putting the 1 billion yen in escrow.

The South Korean president said only a sincere apology will truly settle the issue.

"A treaty or an agreement between governments cannot restore the dignity of many individuals, including the victims of sexual slavery by the Japanese military. A sincere apology and self-reflection must be offered to the victims and accepted," Moon said.

"The victims' wounds will finally heal and they may truly forgive when (Japan) looks squarely at its history that it wishes to avoid and work to make sure such a tragedy in the past will never recur." (Yonhap)