The unification ministry expressed regret Thursday after a UN special rapporteur called on South Korea to reconsider a recently legislated ban on sending anti-Pyongyang leaflets into North Korea, saying the measure was legislated in due democratic procedures.

Earlier in the week, the National Assembly, controlled by the ruling Democratic Party, passed the bill penalizing the sending of anti-Pyongyang propaganda leaflets into the North despite strong objection by opposition party lawmakers.

Special Rapporteur Tomas Ojea Quintana has told a US media outlet that he hopes South Korea will reconsider the legislation before it goes into effect, citing the freedom of expression of activist groups.

"The law was amended after democratic discussion and deliberation according to the procedure stipulated by the Constitution and the law at the National Assembly, which represents the consensus of public opinion," a ministry official said in a press release Thursday.

"We express regret that Rapporteur Quintana has mentioned a need for a democratic institution to conduct appropriate review on this," the official said.

The official also said that Quintana "should see this from a balanced point of view that it has minimally restricted the way of expression of a few in order to protect the lives and safety of many residents in the border areas."

The sending of leaflets has emerged as a major source of cross-border tensions since Pyongyang called it a violation of an inter-Korean summit agreement and threatened to take a series of retaliatory steps against South Korea if it did not stop such activity.

The North even blew up an inter-Korean liaison office in June in anger over the leafleting. (Yonhap)