The United Nations announced on Friday that legal requirements had been met for trials of surviving Khmer Rouge leaders, nearly three decades after Cambodia's genocide began.
An estimated 1.7 million Cambodians -- around a third of the country's population -- died of starvation, forced labour, disease or execution during the Khmer Rouge "killing fields," from 1975 to 1979.
But to date no Khmer Rouge leader has ever faced justice for the atrocities.
A U.N. statement also said that enough money had been raised to fund the special tribunals, which will have a sprinkling of international judges and prosecutors working alongside their Cambodian colleagues.
The United Nations had to certify that the Cambodian court met international justice standards.
Nations at a pledging conference promised about $38 million (19.9 million pounds) for the court action. Japan said it would contribute $21 million. Cambodia will pay some $13 million for the court, estimated to cost $56.3 million over three years.
Secretary-General Kofi Annan notified Cambodian Prime Minister Hun Sen in a letter "that the legal requirements" the United Nations had demanded "had been complied with."
He also said "sufficient pledges and contributions are now in place to fund the staffing of the Extraordinary Chambers and their operations for a sustained period of time," the U.N. announcement said.
The Khmer Rouge's leader, Pol Pot, died in 1998. Many fear other ageing leaders will die before the legal process ends. Up to 10 Khmer Rouge are expected to be tried.
Critics have accused Cambodia of foot-dragging over a tribunal, as some current government officials were once members of the Khmer Rouge, including Mr Hun Sen, a former regimental commander.
The Khmer Rouge regime was overthrown by Vietnam-backed rebels in 1979, who them put Mr Hun Sen in power.
The international community has been pouring money into Cambodia since the early 1990s to help rehabilitate a nation devastated by three decades of civil war and the genocidal rule of the Khmer Rouge. But a third of the 13 million population still lives on less than $1 a day.