North Korea is set to assume the rotating chair of a U.N. forum on nuclear disarmament from Monday, even as the U.S. and South Korea warn Pyongyang is preparing to conduct an underground nuclear test in the near future.

More than 40 nongovernmental organizations (NGOs), including the Committee for Human Rights in North Korea, have called for U.N. Secretary-General António Guterres and member states to boycott sessions of the U.N. Conference on Disarmament during the DPRK’s four weeks as chair, according to the NGO U.N. Watch.