SEOUL, :Kim Yo-jong, the younger sister of North Korean leader Kim Jong-un, and a high level delegation, wrapped up a rare three-day trip to South Korea on Sunday, which Seoul describes a sign of improving bilateral relations despite skepticism expressed by the U.S.

Yo-jong and the officials, led by ceremonial head of state Kim Yong-nam, departed on a North Korean plane from Incheon International Airport, west of Seoul, around 10:24 p.m., after attending a North Korean art troupe's concert in Seoul earlier in the day.

They were seen off by Seoul's unification minister Cho Myoung-gyon and other high-ranking officials.

On Friday, Yo-jong and the delegation arrived in South Korea, marking the first time that a member of the North's ruling family visited the South following the 1950-53 Korean War.

One key question of her visit was what message she would convey from her brother over inter-Korean ties amid a reconciliatory mood between the two Koreas surrounding the North's participation in the PyeongChang Winter Games. The sending of North Korean athletes followed the New Year's message by the North's leader.

On Saturday, the North's delegation paid a visit to President Moon Jae-in at his office Cheong Wa Dae. On the same day, Moon and the North's delegation also jointly attended the opening match of the unified women's ice hockey team, which is comprised of athletes from the two Koreas.

During Saturday's meeting, the North Korean leader's sister, in her capacity as special envoy for her brother, invited the South Korean chief executive to visit the North.

Moon responded that he hopes that the right conditions will be created so that the proposed visit can take place.

Sunday's concert meeting marks the fourth time Moon and Kim Yo-jong have met since they greeted each other during the opening ceremony of the PyeongChang Winter Olympics.

Source: Yonhap News Agency