"Some people have accused me of commanding (the tribunal) from behind," he told reporters. "Everything related to the Khmer Rouge tribunal, I will not talk about it anymore."

The tribunal was created by a 2003 pact between Cambodia and the United Nations to try those responsible for atrocities during the Khmer Rouge rule of the mid-1970s. About 1.7 million people died during the period.

The trials were expected to begin this year. But a dispute over legal fees proved yet another obstacle preventing the tribunal from moving forward.

Human rights groups have accused the Cambodian government of foot-dragging, which the government has repeatedly dismissed.

Hun Sen's critics have also long speculated that he would not like to see too extensive a list of defendants, which could include former middle-ranking Khmer Rouge members who later became his allies. Hun Sen himself was a junior Khmer Rouge member who defected from the group before it was overthrown in 1979.