BBC Correspondent Caroline Gluck: Growing public anger at possibility that the two may escape trial

King Sihanouk said he was taking into account what he called the "wide and understandable discontent felt by the majority of Cambodians".

One of the leaders, Khieu Samphan, made his first public apology this week for the "killing fields" genocide in Cambodia which left up to two million people dead in the 1970s.

King Sihanouk is currently undergoing medical treatment in Beijing

The 76-year-old King's comments in his regular bulletin appear to contradict assurances given by the Prime Minister, Hun Sen, that the two defectors were not likely to face any trial for crimes against humanity and that it would be better for reconciliation in Cambodia to bury the past.

They also follow a warning from the United States that relations with the Cambodian Government could be jeopardised unless the Khmer Rouge leaders were held accountable for their actions.

Cambodian exile Dana Tep tells BBC World why she wants those responsible for genocide brought to justice

The supreme leader, Pol Pot, died in April after a power struggle within the movement.

The King added that any international tribunal would have "the perfect right to take up the case of genocide in Cambodia, because it concerns crimes against humanity".

Anger and dismay

Khieu Samphan, the former nominal leader of the guerrilla movement, and Nuon Chea, its chief idealogue, are currently in the Cambodian capital, Phnom Penh.

They have been meeting senior government ministers and Boutros-Boutros Ghali who is currently in Cambodia as head of the Francophone organisation.

The former UN secretary general was reported as saying the world must respect Cambodia's decision not to try two Khmer Rouge leaders for genocide.

Neither of the latest Khmer Rouge defectors have been charged by a court.

Khieu Samphan: "We have to forget the past"

The BBC Correspondent in Phnom Penh, Caroline Gluck says there is growing anger and dismay at the possibility that the two men may never be made to account for their part in the Khmer Rouge reign of terror.

Two years ago the King, under pressure from the country's joint Prime Ministers, agreed to pardon Ieng Sary, the former Khmer Rouge foreign minister, of a 1979 death penalty after he had been convicted in absentia on genocide charges.

It came shortly after Ieng Sary broke away from the movement's hardliners, bringing several thousand defectors with him - the first major split in the Khmer Rouge.