"The answer to those who lay too much store on Mr. Shin's testimony is to say, 'Sit down and watch hour after hour after hour of the testimony of the witnesses,'" Kirby said of defector Shin Dong-hyuk during the seminar organized by the Center for Strategic and International Studies in Washington.

Shin, one of the best-known North Korean defectors, has apologized for lying about some of the timeline and locations of his survival in North Korean political prison camps, admitting that he spent years in the less brutal Camp 18, rather than Camp 14.

Shin has also testified for the COI investigation and his confession spurred concern it could raise questions about the credibility of testimony from North Korean defectors and deal a blow to international efforts to improve the North's human rights situation.

The COI report called for handling the North's human rights abuses as "crimes against humanity" at the International Criminal Court. The report led to the U.N. General Assembly last year adopting a resolution calling for referring the situation to the ICC.

The U.N. Security Council has also placed the issue on its agenda for ongoing attention.

North Korea has strongly protested against the COI report and the resolution calling for the ICC referral. After Shin's confession, Pyongyang has claimed that the COI report was based on falsehood and therefore the U.N. resolution should be nullified.

Shin's partial withdrawal of his testimony was "immaterial" to the conclusions of the COI report, Kirby said.

"If the DPRK (North Korea) were serious about defending itself against the record revealed by the many witnesses who gave evidence before the COI, it would invite the United Nations, the international media and members of the COI to visit the DPRK to undertake thorough and well-publicized inspections to produce fully documented findings," he said. "The DPRK cannot rely on its own failure to cooperate with the United Nations. Ultimately, the full truth will come out."

Kirby said greater efforts should be made going forward to help the North Korean people know of the COI report.

"How could we make sure that the people of North Korea learn about what the world is saying of their country, of their leaders, of the situation? And that really ought to be a priority because they are a member state of the United Nations. This is a report of the United Nations," he said.

North Korea has long been labeled as one of the worst human rights violators in the world. The communist regime does not tolerate dissent, holds hundreds of thousands of people in political prison camps and keeps tight control over outside information.

But Pyongyang has rejected accusations of human rights abuses as evidence of U.S. hostile policy toward it.

On Monday, the North's deputy U.N. ambassador, Jang Il-hun, held a press conference in New York and demanded Tuesday's seminar be called off, denouncing it as part of U.S. hostile policy and threatening to respond strongly to the event.

Also in attendance at the seminar was Marzuki Darusman, the U.N. special rapporteur on the issue.

"2014 has therefore been a critically important year for the international community's collective engagement on human rights in the DPRK and our efforts to bring relief and justice to its suffering people," Darusman said of the COI report and the General Assembly resolution.

The official also said that the U.N. Human Rights Council will consider adopting another resolution on the North's human rights situation in March.

"This will be another opportunity for the international community to express its disdain around the situation and reiterate its resolve to put an end to the ongoing violations in the DPRK," he said.

(Yonhap)