UN chief Ban Ki-moon drew a parallel Thursday between Syria's civil war and the Rwandan genocide, describing both conflicts as gross failures of the international community to stop deadly wrongdoing.
Marking the 20th anniversary of mass killings in the African state, Ban said the United Nations had learned lessons in trying to prevent such a human tragedy, though he hinted that such an event could again be occurring.
"The Rwandan genocide was an epic failure of the international community to take action in the face of atrocity crimes," said the UN Secretary General.
"We know more keenly than ever that genocide is not a single event, but a process that evolves over time."
Noting that with "courage and political will, genocide can be prevented," Ban, however, said that the killings in Syria continue. The death toll is currently estimated at more than 140,000, with no sign of ending.
An estimated 800,000 people, the overwhelming majority of them ethnic Tutsis, were killed in Rwanda's 1994 genocide.
"Our collective failure to prevent atrocities in Syria over the past three years is a shameful indictment of the international community," said Ban, also mentioning rising hatred against migrants, Muslims and the Roma community in Europe.
The UN Security Council has been sharply divided over the Syrian conflict, but on Saturday it unanimously adopted a resolution calling for humanitarian aid convoys to be allowed access across the war-torn country.