WASHINGTON (AP) — The leader of a U.N. commission of inquiry that found North Korea committed crimes against humanity said Tuesday that members of the panel are ready to go anywhere to talk to the North's government — but it refuses to engage.

Michael Kirby addressed a conference in Washington marking the anniversary of the publication of the commission's landmark report, which called for North Korea to be referred to the International Criminal Court.

North Korea on Monday demanded that the conference be scrapped, claiming the U.S. ignored its offer to attend and defend itself.

Among those speaking were North Korean defectors, who alleged torture of prison camp inmates, starvation and forced abortions.

The State Department said the conference was a privately organized event, although a U.S. rights envoy attended. It was held by the Center for Strategic and International Studies, a nongovernment think tank.

The U.S. restricts North Korean diplomats to traveling within a 25-mile radius of midtown Manhattan in New York, where they retain a diplomatic mission at the United Nations. They must request permission to go farther.

"I would be quite happy if they were down here. This is a public session," said Kirby, a retired Australian judge.

Kirby led the three-member commission, which included Indonesian former attorney general, Marzuki Darusman, who still serves as U.N special rapporteur on human rights in North Korea.

"We have reached out to them. I will go anywhere, the members of the commission of inquiry, the special rapporteur will go anywhere to engage them but they won't engage with us except on very limited terms favorable to them," Kirby said.

North Korea was enraged by the commission, which estimated that more than 80,000 people are held in the nation's gulag. The commission also wrote to North Korean leader Kim Jong Un warning that he could be held accountable for crimes against humanity.

The North accuses the U.S., which supported the commission's creation, of using the human rights issue as a pretext to overthrow it. Relations already badly strained by Pyongyang's development of nuclear weapons have only worsened.

"We are not guilty of any crime," North Korea's U.N. Ambassador Jang Il Hun told reporters at the United Nations in New York on Monday. He said North Korea would respond "very strongly" to Tuesday's conference.

Victor Cha, a former senior U.S. official and event organizer, said the North Korean call for the conference to be canceled "only ensured we were going to have it."

It was one of the few public events held in Washington on a day when the U.S. government was shut down by snow and many other events were canceled.

South Korean human rights envoy Jung-hoon Lee said that sent a message to Pyongyang: "if you don't relent, we won't either."

U.S. rights envoy on North Korea, Robert King, said because of the international scrutiny of its human rights record, Pyongyang "feels increasingly compelled to respond to what's happening."

Darusman said commission's findings could be a tipping point that presages reforms within North Korea, but said the path ahead for now was to build a case in anticipation that there would one day be a judicial process.

Defector Gwang Il Jung spoke Tuesday of "subhuman" treatment in the political prison camp where he was held until 2003. He said starving inmates would pick grains of corn from human feces. Those injured hauling lumber in the winter were left to die and their bodies dumped.

"What was taking place was beyond our imagination," he said.

North Korea denies the existence of the political prison camps and has described those who testified to the commission as "human scum." Gwang challenged North Korea to conduct its own investigation and question them.

Kirby called for the Security Council to refer the case of North Korea to the International Criminal Court, saying if the referral was not approved, "those who stop accountability can answer before the bar of the international community."

Permanent council member China, which is North Korea's only major ally, would be likely to use its veto power. It is criticized in the report for its repatriation of North Korean refugees.