Early in his administration, Trump was shown a scale model of North Korea's sprawling nuclear bomb test site with a removable mountaintop and a miniature Statue of Liberty inside so he could grasp the size of the facility, two USA officials said.
On Saturday, North Korean leader Kim Jong-un announced he was suspending his country's nuclear and missile tests.
In 2007, then South Korean President Roh Moo-hyun's public approval ratings shot up when he met with the North's Kim Jong Il.
It will be the high point so far of a rapid diplomatic rapprochement on the peninsula, ahead of a much-anticipated meeting between Mr Kim and US President Donald Trump.
China said more than 237,000 Chinese visited North Korea in 2012, but stopped publishing the figures in 2013.
North Korean leader Kim Jong Un said last week that he was ordering the test site to be shuttered, declaring that North Korea no longer needed to test nuclear weapons.
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.
"That's what makes this summit all the more hard", he added.
"(Seoul) takes the move as a sign that the North is not considering just the inter-Korean summit, but looking ahead to the US-North Korea talks, and worldwide cooperation that will follow".
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.
After the morning session the two parties will have lunch separately before they plant a tree together in a symbolic ceremony.
"We hope to call this the Panmunjom Declaration", Im said.
The list of Moon's entourage includes Im Jong-seok, presidential chief of staff; Chung Eui-yong, top national security advisor for the president; Suh Hoon, chief of the National Intelligence Service (NIS); Foreign Minister Kang Kyung-wha; Defense Minister Song Young-moo; Unification Minister Cho Myoung-gyon; and Jeong Kyeong-doo, the head of South Korea's Joint Chiefs of Staff (JCS).
While Kim may not be able to control every aspect of what happens on the South Korean side of the DMZ, Seoul seems eager to make sure things go smoothly, even preparing a banquet that includes dishes from Switzerland, where Kim studied during his teens.
"The reunion of families separated during the Korean War, releasing foreigners who were arbitrarily detained, or addressing the detrimental impact of sanctions on the economic and social rights of the DPRK population, are some of the less controversial issues that can be first included in these talks", he said.
"We did not expect this".
Im said President Moon will greet Kim, chairman of the State Affairs Commission of the DPRK, on the MDL, noting that Kim will walk over the MDL under the escort of South Korea's honor guard.