Reuters, Beijing : China rejected what it said was “unreasonable criticism” of Beijing in a new UN report on human rights abuses in North Korea, but it would not be drawn on whether it would veto any proceedings in the Security Council to bring Pyongyang to book. North Korean security chiefs and possibly even Kim Jong Un, the leader of the country, should face international justice for ordering systematic torture, starvation and killings comparable to Nazi-era atrocities, UN investigators said on Monday. The unprecedented public rebuke and warning to a head of state by a UN inquiry is likely to further antagonize Kim and complicate efforts to persuade him to rein in his isolated country’s nuclear weapons program and belligerent confrontations with South Korea and the West. The UN investigators also told China, the North’s main ally, that it might be “aiding and abetting crimes against humanity” by sending migrants and defectors back to North Korea to face torture or execution, a charge that prompted a sharp rebuke from Beijing. “Of course we cannot accept this unreasonable criticism,” Chinese Foreign Ministry spokeswoman Hua Chunying said at a briefing on Tuesday. “We believe that politicizing human rights issues is not conducive towards improving a country’s human rights. “We believe that taking human rights issues to the International Criminal Court is not helpful to improving a country’s human rights situation.” Hua would not answer what she said was a “hypothetical question” on whether China would use its veto powers if the report was brought to the UN Security Council for further action. Diplomats have said China will most likely block any such proceedings. Asked why China blocked UN investigators from going to the North Korean border, across which many North Koreans cross illegally, Hua said she could not comment and would have to look into the matter.