Choi In-guk, left, and his mother, Ryu Mi-yong, hold hands during a cross-border reunion of separated families in August 2000 when Ryu visited Seoul after defecting to the North with her husband in 1986. / Korea Times file

By Yi Whan-woo

The son of a late South Korean couple who defected to North Korea in 1986 arrived in Pyongyang, Wednesday, for a ceremony to mark the first anniversary of his mother's death.

The Ministry of Unification said the son, Choi In-guk, is the first South Korean citizen to visit the reclusive state since President Moon Jae-in took office in May.

Choi is scheduled to stay in North Korea for four days and return home Saturday.

"We approved Choi's trip to the North on humanitarian grounds," the ministry said.

Choi, 71, is the second son of Ryu Mi-yong, the late chairwoman of the central committee of the Chondoist Chongu Party, the only quasi-religious party in the North in alliance with the ruling Workers' Party.

Ryu died at age 95 on Nov. 23, 2016.

The fathers of Ryu and her late husband, Choe Deok-sin, were independence activists during Japan's 1910-45 occupation of the Korean Peninsula and also believers of the native Korean religion Cheondoism.

The two fathers defected to the North during the 1950-53 Korean War and spent the rest of their lives there.

Choe, also a Chondogyo believer, served as the foreign minister as well as South Korea's ambassador to West Germany under President Park Chung-hee.

He later had uneasy relations with Park and fled to the United States with his wife before defecting to North Korea in 1986.

Choe is one of the few high-profile South Koreans who fled to the repressive state.

He led the Chondoist Chongu Party until he passed away in 1989. Ryu succeeded him in 1993.

The Ryu-Choe couple had two sons and three daughters when they defected to the North. But their children were not "old enough" back then and did not accompany their parents, according to the Central Headquarters of Cheondogyo in Seoul.

Choi briefly met his mother during the cross-border reunion of separated families in August 2000 when Ryu led respective family members from the North on a visit to Seoul.

Choi visited North Korea in November 2016 when Ryu died.

However, he did not have a chance to visit Pyongyang and commemorate the anniversaries of his father's death, the Central Headquarters of Cheondogyo said.