UNITED NATIONS — The chief U.N. investigator into human rights abuses in North Korea appealed to the U.N. Security Council on Thursday to refer the situation in the reclusive Asian state to the International Criminal Court for prosecution.

"In a week of many grave human rights matters occupying the attention of the members of this council, we dare say that the case of human rights in the DPRK (Democratic People Republic of Korea) exceeds all others in duration, intensity and horror," Michael Kirby told an informal meeting of the 15-member council.

A year-long U.N. inquiry, led by Kirby, concluded in a Feb. 17 report that North Korean security chiefs and possibly even Supreme Leader Kim Jong Un himself should face international justice for ordering systematic torture, starvation and killings comparable to Nazi-era atrocities.

The inquiry recommended the United Nations Security Council refer the situation in North Korea to the International Criminal Court (ICC), which investigates war crimes, crimes against humanity, genocide and the crime of aggression.

The court can investigate crimes in states that have joined the institution, but it can only pursue crimes in non-member states if authorized by the Security Council, which was the case with Libya and Darfur, Sudan.

The U.N. inquiry cataloged massive human rights violations in North Korea that it said amount to crimes against humanity.

"Only the Security Council can set in train immediate, impartial and just action to secure accountability, fulfill the responsibility to protect, put human rights right and stop grave human rights violations from undermining peace and security," Kirby told the Security Council meeting, which was also open to other U.N. member states and activist groups.

But China, a veto-wielding Security Council member, has signaled that it could shield its neighbor North Korea from potential prosecution. China told the Human Rights Council in Geneva last month that the U.N. inquiry had made unfounded accusations and recommendations "divorced from reality."

On the prospect of an ICC referral by the Security Council, a U.N. council diplomat, speaking on condition of anonymity, said: "We're not going to see any rapid progress on this."

China has acted as North Korea's protector on the Security Council. Though on the issue of Pyongyang's nuclear and ballistic missile programs Beijing has shown a willingness to allow council reprimands, while at the same time working to limit the impact of any action.

North Korea is under an array of U.N., U.S. and other national sanctions due to repeated nuclear and ballistic missile tests since 2006 in defiance of international demands to stop.

North Korea "categorically and totally" rejected the accusations set out in a 372-page report, saying they were based on material faked by hostile forces backed by the United States, the European Union and Japan.

The U.N. Human Rights Council in Geneva adopted a resolution last month asking the Security Council to consider referring North Korea to the ICC. China and Russia, also a veto-wielding Security Council member, voted against the resolution.