South Korea’s unification ministry has urged human rights groups to “refrain from” sending anti-regime leaflets to North Korea, while warning Pyongyang that Seoul will respond “strongly” to threats of “retaliation” against ROK citizens.

The statement on Friday comes as a U.S. nongovernmental organization prepares to host an annual series of events on DPRK human rights called North Korea Freedom Week, which a prominent defector-activist has used as an occasion to launch balloons carrying leaflets in the past.

“The South Korean government has requestedmultiple times that civic groups refrain from disseminating items such as anti-DPRK leaflets,” unification ministry deputy spokesperson