The former head of state of Cambodia's 1970s Khmer Rouge regime has rejected the charges against him as his trial for genocide ended.
Khieu Samphan, 85, said the allegations were concocted by the country's traditional enemy, neighbouring Vietnam.
He delivered his closing remarks in front of the UN-assisted tribunal in Phnom Penh where he and a colleague are also accused of responsibility for implementing policies leading to murder and rape, among other crimes.
Khieu Samphan denied knowing about matters including forced marriage and the grievous fate of minorities while the Khmer Rouge held power, saying he only discovered them after the regime's fall in 1979 and during his trial.
He said he was made aware of the accusations of suffering under the Khmer Rouge regime, "but the term murderer I categorically rejected".
The Khmer Rouge is blamed for the deaths of 1.7 million Cambodians from execution, starvation and inadequate medical care during its 1975-79 rule.
Khieu Samphan's 90-year-old co-defendant Nuon Chea, right-hand man to late Khmer Rouge leader Pol Pot, did not appear in court.
His lawyer Victor Koppe delivered remarks saying that his client regarded the tribunal as a "show trial' and "victor's justice".
The two men already received life sentences in 2014 for crimes against humanity.
The proceedings against them were split into two parts by the tribunal for fear that the defendants might die before a verdict was reached if it was kept as one.
Also separately convicted earlier was the head of the Khmer Rouge prison system, who ran a torture centre in Phnom Penh.
Khieu Samphan described the claim of genocide as "Vietnamese propaganda", a defence he and other former Khmer Rouge leaders have made previously.
Cambodians have long been suspicious of their much bigger eastern neighbour, and prejudice against Vietnamese is widespread.
Even the 1978 invasion of Cambodia by Vietnam to oust the Khmer Rouge raised suspicions about Hanoi's motives among many Cambodians.
The genocide case includes the killing of ethnic Vietnamese by the Khmer Rouge.
Khieu Samphan sounded another familiar theme in also casting blame on the United States for Cambodia's problems.
The US heavily bombed the Cambodian countryside during the 1970-75 civil war that led to the Khmer Rouge seizing power.
Critics of the US action charge that the intensive bombing radicalised Cambodian peasants and served as a recruiting tool for the Khmer Rouge.
"I want to bow to the memory of all the innocent victims but also to all those who perished by believing in a better ideal of the brighter future and who died during the five-year war under the American bombardments and (in) the conflict with the Vietnamese invaders," Khieu Samphan said.
"Their memory will never be honoured by any international tribunal."