U.S. President Donald Trump has agreed to meet with North Korean leader Kim Jong Un in Pyongyang “by May” to discuss ending the North’s threatening nuclear program.

The surprising announcement was made Thursday evening by Chung Eui-yong, the head of South Korea’s National Security Office, who was in Washington to brief Trump, and White House officials including National Security Advisor H.R. McMaster, on diplomatic progress made during his visit to Pyongyang earlier this week. He also conveyed a verbal invitation from the North Korean leader to the U.S. president.

“President Trump appreciated the briefing and said he would meet Kim Jong Un by May to achieve permanent denuclearization,” Chung said.

Shuttle diplomacy

Chung led a South Korean diplomatic delegation that met with the North Korean leader in Pyongyang on Monday. Afterward, he communicated Kim’s willingness to engage with the U.S. in denuclearization negotiations, and his promise to suspend nuclear and missile tests while talks are underway.

Pyongyang’s position, as stated by Chung, is that “it would have no reason to possess nuclear weapons should the safety of its regime be guaranteed and military threats against North Korea be removed.”