In the Panmunjom Declaration which was signed at the end of the first summit between President Moon Jae-in and North Korean leader Kim Jong-un, the two leaders agreed to create the joint liaison office to allow constant communication, support interactive summits between the two Koreas, and promote civilian exchanges.
Moon will head to Pyongyang in the week of 17 September for a third summit with the North's leader Kim Jong-un, as US-led efforts to persuade Pyongyang to give up its nuclear weapons have stalled.
That would entail North Korea surrendering 15-20 nuclear warheads and missiles in return for Washington lifting economic sanctions, or at least the establishment of a liaison office with Pyongyang, and an end of war declaration.
The South Korean government also coordinated the crossing of delegations for a planned opening ceremony on Friday of a new liaison office in Kaesong, which is just north of the DMZ and was the site of a defunct joint business venture.
In this November 29, 2017, file photo provided by the North Korean government shows North Korean leader Kim Jong Un, third from left, and what the North Korean government calls the Hwasong-15 intercontinental ballistic missile, in North Korea.
Unification Minister Cho Myoung-gyon and other people from the parliament and academia will attend the ceremony.
"North Korea is willing to denuclearize and therefore willing to discard existing nuclear weapons... and the USA is willing to end hostile relations with the North and provide security guarantees", Moon said.
The liaison office in the empty industrial park occupies a building previously used by junior-level South Korean government officials who oversaw the private sector operations at the complex.
"Eighty tons of heavy oil in Kaesong is for the consumption of South Korea officials", Moon, who also noted that Seoul contacted the United Nations sanctions committee over the issue, said.
US documents sent to the Security Council committee monitoring sanctions against North Korea and obtained by AP cited 89 instances between January 1 and May 30 in which North Korean tankers likely delivered refined products "illicitly procured" via transfers from other ships at sea.
During the previous meetings with Moon and a separate historic summit with U.S. President Donald Trump, Kim has expressed his vague commitment to complete denuclearization of the peninsula. But nuclear diplomacy was later stalemated as US officials demanded Kim take more significant steps before receiving concessions like a joint declaration to end the Korean War.
High-profile politicians and businessmen are expected to accompany Moon to Pyongyang. He said he will focus on facilitating talks between the United States and North Korea and finding ways to ease the military standoff along the Koreas' heavily fortified border. It said the live coverage will include key moments such as when the leaders greet each other in Pyongyang on Tuesday.