UNITED NATIONS: A group of prominent former world leaders founded by Nelson Mandela said Friday that dialogue and diplomacy are the only ways to end the devastating war in Ukraine.

Former Irish president Mary Robinson, the chair of the group known as The Elders, said in a meeting this summer that the group delivered that message to Ukrainian President Volodymyr Zelenskyy. She told him that he needed to start thinking of ways to end the conflict.

“We need to encourage more thinking about how it will end in order to get the idea that this needs to end, as opposed to increasing the military arsenal on both sides and the devastation to the population in Ukraine,” said Robinson, who also served as U.N. high commissioner for human rights.

The Elders have condemned Russia’s Feb. 24 invasion of Ukraine as “a flagrant violation of the United Nations Charter and a reckless, unjustifiable act of aggression that threatens to destabilize world peace and security.” In late September, The Elders also condemned Russia’s illegal annexation of four Ukrainian regions and defended Ukraine’s right to defend its territory and sovereignty.

Zeid Ra’ad al-Hussein, a previous U.N. human rights commissioner, agreed that diplomacy and negotiation were the only way out of the war, but he stressed that did not mean asking Ukraine to cede its sovereignty, since it was the victim of unprovoked Russian aggression.

He hinted that a settlement of the conflict could instead involve Russia receiving a concession “from another direction,” a possible reference to NATO, or one of its key members.

Vladimir Putin complained long ago that the Western alliance was moving closer to its borders, which he used to justify his invasion of the country.

Former Mexican president Ernesto Zedillo said that despite economic sanctions imposed by the European Union and the United States “the flow of resources to finance this war has continued,” including the huge influx of oil revenue to Russia.

“I think there should be less hypocrisy about the way in which this bellicose economic war is being fought,” he said.

Zedillo also accused Russia of committing crimes that the International Criminal Court is charged with addressing — genocide, war crimes and crimes against humanity — and that have to be decided by “due process.”