Mr Moon said he wanted to ensure inter-Korean meetings ahead of next month’s Winter Olympics led to talks between officials from Pyongyang and Washington over Kim Jong-un’s weapons programmes.
After a year of growing tensions in the region, diplomacy focused on sport enabled the International Olympic Committee to announce that North Korea will send 22 athletes to the Winter Games.
Mr Moon said the Olympics provided a “precious chance to open the door” for a peaceful resolution of the North Korean nuclear issue and establishment of peace on the Korean peninsula.
But he warned: “But no one can be optimistic about how long the current mood for dialogue will last.
“We need wisdom and efforts to sustain the dialogue opportunities beyond the Olympics so that the inter-Korean talks will lead to talks between the United States and North Korea and other forms of dialogue”.
Opinion polls show most South Koreans welcome the North’s participation in the Games but conservative opponents staged a small protest as a delegation from Pyongyang inspected venues in Seoul for cultural events to be held on the sidelines.
Police were forced to intervene when a picture of Kim was burned on the steps of Seoul’s central train station and protesters chanted the despised dictator had “snatched” attention for the showpiece event from South Korea.
A series of events including concerts, joint training exercises and sporting demonstrations are planned around Olympics.
The North Korean delegation was led by popular female singer Hyon Song-wol who smiled and waved to a crowd at the train station before the protest began.
She said: “Seeing the citizens here welcoming us, I feel we will be able to successfully complete the concert.”