The presidential office said it will work to secure the release of six South Korean nationals currently detained in North Korea through dialogue with the regime.

The top office said on Thursday that six South Koreans, including three North Korean defectors, have been held in the North on charges including espionage since various dates between 2013 and 2016.

The presidential office said that three of the six detainees, who were taken into custody in 2013 and 2014, are missionaries. It did not disclose details of the three defectors to protect their families in the North.

The office said that the suspension of inter-Korean dialogue and exchange has caused prolonged suffering.

Asked about the matter during a news conference with foreign journalists the previous day, President Lee Jae Myung said he lacked specific information but would look into the situation further.