In stunning and unexpected announcement late Tuesday, Seoul and Pyongyang agreed to a deal that could see South Korean President Moon Jae-in and North Korean leader Kim Jong Un meet for a rare leaders' summit at the two countries' heavily armed border next month.

Moon's top security adviser, Chung Eui-yong, who had returned from meeting Kim in Pyongyang earlier in the day after leading a South Korean delegation, told a news briefing that the two Koreas had agreed to open a communication hotline between Moon and Kim to "reduce military tensions," the South's Yonhap news agency quoted Chung as saying.

The two leaders were expected to hold their first telephone conversation before the planned summit, he said.