US and North Korean officials met Sunday at a border truce village as preparations resumed for a high-stakes, high-drama summit that President Donald Trump suggests could help the North realize its “brilliant potential”.

“I truly believe North Korea has brilliant potential and will be a great economic and financial Nation one day,” Trump said on Twitter.

“Kim Jong Un agrees with me on this. It will happen!,” the President said, confirming that a US team “has arrived in North Korea to make arrangements for the summit” between himself and North Korean leader Kim.

His upbeat language contrasted sharply to that of only three days earlier, when Trump cancelled the planned summit, citing “open hostility” from the North. An extraordinary flurry of diplomacy since then much of it led by South Korea appears to have put the meeting back on track.

Kim and South Korean President Moon Jae-in met Saturday at the Panmunjom border truce village, in a surprise bid to salvage the June 12 summit planned for Singapore.

Announcing the lower-level talks held Sunday, State Department spokesperson Heather Nauert said, “We continue to prepare for a meeting between the President and North Korean leader Kim Jong Un.”

The Washington Post reported that the US delegation to the Panmunjom meetingĀ  in the Demilitarized Zone between North and South Korea was led by Sung Kim, a former US ambassador to South Korea and former nuclear negotiator with the North. It said the Americans met with North Korean Vice Foreign Minister Choe Son Hui.

Tokyo stocks opened higher Monday on the news, although trading was thin.

“Excessive worries receded as efforts resumed for a summit between the US and North Korea,” Okasan Online Securities strategist Yoshihiro Ito said in a commentary, which added that uncertainty remains.

The United States currently has no ambassador to South Korea, even as it takes up one of the most delicate diplomatic challenges in years.

It remains far from clear how Trump and Kim might be able to bridge what appear to be vast differences in their expectations for what would be a historic meeting. But analysts on Sunday expressed increasing confidence that it will take place.