A leading local rights organization has issued a sharp warning to UN Secretary-General Ban Ki-moon, urging him to take a hard stance on the Khmer Rouge tribunal, which has come under increased scrutiny for its handling of a controversial case at the court.

The Cambodian Human Rights Center urged the UN not falter in handling trials of senior leaders, especially after Prime Minister Hun Sen told Ban in a meeting this year he would not allow more indictments at the court.

“The UN should not step backward on human rights and succumb to threat,” Ou Virak, president of the rights group, told “Hello VOA” Wednesday. “It should work closely with the government and tell them that the role of the UN is not to help the government, but its people, through the cooperation with the government and civil society.”

The UN-backed tribunal has come under increased pressure in recent months, after investigating judges concluded their work in Case 003, which has two suspects whose indictments Hun Sen objects to. Ban said in a statement last month that the UN was not ignoring that case and another, to refute media reports and concerns the UN was not fully pursuing trials against former Khmer Rouge.

Ou Virak said he asked the international agency to “send a message to the government that the UN can only work with the government so long as the cooperation is for the benefit of the people.”

Cambodia’s relations with the UN office have been strained in recent years. Cambodia threatened to expel the UN’s country head earlier this year for comments he made over the anti-corruption law.

Koy Kuong, a spokesman for the Ministry of Foreign Affairs, said “some” UN representatives were working under their own “personal views,” and not under the agreements the UN has made with the government. “Therefore, we only remind them to perform their work under the terms of agreement,” he said.