SEOUL, June 12  -- South Korean President Moon Jae-in on Monday reiterated the need to denuclearize the Korean Peninsula during a meeting with the visiting special envoy of Japanese Prime Minister Shinzo Abe.

Toshihiro Nikai, secretary-general of Japan's ruling Liberal Democratic Party, met with Moon in the presidential Blue House in Seoul as Abe's special envoy. He carried a letter from Abe, according to the Blue House.

It was the reciprocal visit of Moon's dispatch of his special envoy to Japan following his inauguration on May 10.

During the meeting, Moon said the denuclearization of the Democratic People's Republic of Korea (DPRK) will be mandatory for peace in the world and Northeast Asia as well as for South Korea's survival.

From that perspective, Moon said, South Korea and Japan were on the same page. Moon shared Abe's view that stronger sanctions and pressures would be needed to completely denuclearize the peninsula.

Moon, however, noted that it would not end up with pressures and sanctions as the DPRK should be brought to a dialogue table for the denuclearization, saying it would be necessary to send a message that relevant parties will help if Pyongyang gives up its nuclear program.

The South Korean leader vowed to closely cooperate with his U.S. and Japanese counterparts in dealing with the DPRK's nuclear ambition.

Touching on the South Korea-Japan relations, Moon said the bilateral agreement on the wartime sexual slavery victims, called comfort women, was not acceptable to South Korean people, especially the victims themselves.

Seoul and Tokyo, Moon said, should squarely face that point and recognize that it takes time to solve the issue.

The final and irreversible agreement on the comfort women was reached in December 2015 under the Park Geun-hye government despite strong opposition from both conservative and liberal South Koreans.