UN High Commissioner for Human Rights Navi Pillay told reporters in Geneva she was “disappointed” that China welcomed Sudan’s President Omar Bashir during a visit this week, rather than arrest him to ensure he stands trial.

Pillay said that “the whole world favors trial” for Bashir on charges of war crimes, crimes against humanity and three counts of genocide, the first time the world’s permanent war crimes tribunal issued genocide charges.

China has a duty to enforce warrants by the International Criminal Court, she said, despite the fact that it’s not a member of The Hague, Netherlands-based tribunal. The Sudanese leader defiantly rejects the charges and the authority of the court.

“There is a duty and a responsibility on the part of every government including China to assist the court in bringing to justice individuals who have been indicted by the court,” Pillay said. “It’s disappointing when states do not deliver on this responsibility.” China’s mission to the UN in Geneva did not immediately respond to requests for comment.

Even nations that are members of the ICC, such as Chad and Kenya, have declined to carry out the court’s international warrant, citing fears it could derail efforts to create peace in Sudan’s western Darfur region.

An arrest warrant for Bashir said last year there were “reasonable grounds to believe” that since April 2003 Sudanese forces attempted genocide against the Darfur tribal groups Fur, Masalit and Zaghawa. Judges also issued a warrant in 2009 against the president over crimes against humanity in Darfur. The UN says the conflict has left up to 300,000 people dead and forced millions to flee their homes.

The UN Security Council granted the ICC jurisdiction over Sudanese war crimes in 2005, but the court has no police force or ability to enforce its orders without cooperation from governments.

The Sudanese leader has continued to visit countries where he is not likely to face arrest, such as Ethiopia, which is not a member of the ICC, and Saudi Arabia, where he went on a Muslim pilgrimage.

Bashir, who left Beijing on Wednesday for the eastern Chinese port city of Qingdao, was expected to leave China later Thursday to return to Sudan.

Pillay said she could assure everyone, based on her experience as a judge for the ICC, that it would conduct a fair trial.

“It’s not like we’re calling for an execution of someone, we’re calling for an arrest of someone,” she said.

Luis Moreno Ocampo, the ICC’s chief prosecutor, told the UN Security Council last month that genocide and crimes against humanity have continued in Darfur, masterminded by Bashir.

Moreno Ocampo said Bashirwas behind air attacks on civilians and the killing of members of the Fur, Masalit and Zaghawa. The Security Council referred the Darfur conflict to the court in 2005.

Sudan’s UN Ambassador Daffa-Alla Elhag Ali Osman told the council, however, that Sudan is not a member of the court and Moreno Ocampo’s statement and written report to the council in New York were “overloaded with ... unfounded accusations” of rape, killing, war crimes and genocide.