North Korea's leader Kim Jong Un and the South's president Moon Jae-in will meet at the Military Demarcation Line that divides the peninsula before their summit Friday, Seoul said, in an occasion laden with symbolism.
Moon will greet his visitor at the concrete blocks that mark the border between the two Koreas in the Demilitarized Zone, the chief of the South's presidential secretariat Im Jong-seok said.
When Kim steps over the line he will become the first North Korean leader to set foot in the South since the Korean War ended 65 years ago.
The North Korean delegation, which includes Kim's sister Kim Yo Jong, who in February attended the Pyeongchang Olympics opening ceremony, will attend the official welcoming ceremony at 9:40 a.m.
The first talks at the historic inter-Korean summit, which will be held at the Peace House, just south of the border at the joint village of Panmunjom, will begin at 10:30 a.m. after Kim signs a guestbook and poses for commemorative photos, Im said.
Later in the day, the two leaders will plant a pine tree dating from 1953 when the Korean War armistice was signed, before an agreement is signed and announced, he added.
At 6:30 p.m. Kim and Moon will attend a welcoming banquet, to be followed by a farewell ceremony during which video showing images of the Korean Peninsula will be projected onto the Peace House.
The meeting will be only the third of its kind, following summits in Pyongyang in 2000 and 2007, and the high point so far of a rapid diplomatic rapprochement on the tension-wracked peninsula, ahead of a much-anticipated meeting between Kim and U.S. President Donald Trump.
The North's nuclear arsenal will be high on the agenda. Pyongyang has made rapid progress in its weapons development under Kim, who inherited power from his father in 2011.
Last year it carried out its sixth nuclear blast, by far its most powerful to date, and launched missiles capable of reaching the U.S. mainland, sending tensions soaring as Kim and Trump traded personal insults and threats of war.
Moon seized on the South's Winter Olympics as an opportunity to try to broker dialogue between them.
But Im played down expectations, saying that the North's technological advances meant deal would need to be "fundamentally different in nature from denuclearization agreements reached in the 1990s and early 2000s".
"That's what makes this summit all the more difficult," he added.
"The difficult part is at what level the two leaders will be able to reach an agreement regarding (the North's) willingness to denuclearize," he said, "and how it will be expressed in text".
In the past, North Korean support for the "denuclearization of the Korean peninsula" has been code for the removal of U.S. troops from the South and the end of its nuclear umbrella over its security ally -- prospects unthinkable in Washington.
Trump has demanded the North give up its weapons, and Washington is pressing for it to do so in a complete, verifiable and irreversible way.
In recent days Seoul has promoted the idea of a path towards a peace treaty to formally end the 1950-53 Korean War, which stopped with a ceasefire, but Im did not mention the issue.
Reunions of families left divided by the conflict could also be discussed, and Moon has told Japanese Prime Minister Shinzo Abe that he would raise the emotive subject of Japanese citizens kidnaped by the North's agents.