North and South Korea held talks on connecting the railways that run across their border, a physical link that would transform the relationship between the two sides of the divided peninsula.
The discussions, the first on the issue for 10 years, took place in the truce village of Panmunjom in the Demilitarized Zone.
A rail line already exists from Seoul to Pyongyang and on to Sinuiju on the Chinese border, originally built by Japan in the early 20th century, long before the Korean War and decades of division.
Kim and Moon agreed to adopt practical steps towards the connection of the railways at their first summit in April.
Moon has also shared his vision of linking the inter-Korean lines to trans-Siberian railways offering a route to Europe, saying it would bring "huge economic benefits" to Seoul and Pyongyang as well as Russia.
The rapprochement on the Korean peninsula was triggered earlier this year when Kim decided to send athletes, cheerleaders and his sister as an envoy to the Winter Olympics in the South.
Later, the US, too, engaged in diplomacy with Pyongyang, which culminated in a summit between Kim and US President Donald Trump in Singapore on June 12.
