Kim Jong Un has invited the South Korean president to visit him in Pyongyang in what could be the first summit between the leaders of the two Koreas since 2007.
The invitation was delivered by North Korean leader's sister, Kim Yo Jong, who is in the south visiting the Winter Olympic Games.
The 28-year-old is a crucial part of the North's Games delegation led by Kim Yong Nam, North Korea's nominal head of state.
South Korean President Moon Jae-in hosted talks with the delegation on Saturday in the hope that improving relations between the two countries could help resolve differences over the North's nuclear and missile programmes.
Kim Jong Un's sister is the first member of the ruling Kim family to cross the border into the south since the Korean war ended in 1953.
Moon was heard asking the visiting delegation "I appreciate you stayed late out in the cold, are you all well?" before the talks proceeded behind closed doors.