South Korean officials announced on Thursday that a deal has been reached to hold a summit in Pyongyang from September 18-20. The summit is to focus on “practical measures” which could be taken for denuclearization of the Korean Peninsula.

South Korean national security adviser Chung Eui-yong told reporters that North Korea’s Kim Jong Un has “reconfirmed his determination to completely denuclearize,” and that he continues to have faith in President Trump.

The commitment to denuclearize is a major announcement, as US officials have been increasingly dubious about that, and complaining about the lack of quick progress. North Korean officials say Kim is frustrated by the doubts expressed in the international community about his will to preemptively denuclearize. He told Chung that he feels the good faith moves made by North Korea should be reciprocated.

North Korea has been increasingly vocal about its desire for a peace treaty. The US has been resisting such calls, saying they intend to do nothing until the denuclearization is completed. The US has also resisted any easing of sanctions, and actually pushed for more restrictions on North Korea’s international trade since the denuclearization was announced.

South Korea has been much more interested in making a peace deal with the North, ending the Korean War. They have also been trying to steer the US on dealing with them in the meantime. This is likely to mean South Korea attempting to clarify a path to peace as well as denuclearization in the summit, then pushing the US to accept this after the fact.