Seoul has expressed deep regret over a North Korean propaganda broadcast during which a detained South Korean citizen claimed the government's involvement in missionary activities to North Koreans.

Unification Ministry Spokesman Jeong Joon-hee on Wednesday addressed South Korean citizen Kim Kuk-ki's appearance on North Korean media the previous day.

The spokesman said that Seoul deeply regrets how the North is unilaterally distorting the truth while detaining a South Korean national for a long period of time.

Jeong then urged the North to swiftly release all South Koreans who are being held in the North against their will.

Appearing on North Korean media on Tuesday, the detained South Korean missionary stated his religious activities were carried out under orders from the South’s National Intelligence Service.