Kim Jong-un has agreed to shut down one of North Korea's main missile testing and launch sites, says South Korea's President Moon Jae-in.
After meeting in Pyongyang, the two leaders "agreed on a way to achieve denuclearisation," said Mr Moon.
The agreement was described by Mr Kim as a "leap forward" towards military peace on the peninsula.
Mr Kim also said he hoped to "visit Seoul in the near future" - he would be the first North Korean leader to do so.
Summit results: Denuclearisation
The main focus of the summit was the issue of denuclearisation. While the US and North Korea agreed in broad terms earlier this year to work towards that goal, negotiations have stalled.
Pyongyang has now sought to reconfirm its commitment.
Mr Moon said Mr Kim had "agreed to permanently close the Tongchang-ri missile engine test site and missile launch facility" and, crucially, that this would be done "in the presence of experts from relevant nations".