"What else is it if not genocide to indiscriminately bomb civilians, churches, the historical monuments of a people in spite of all international laws," he said in an interview with the Italian daily, La Repubblica, Oct. 19.
Only by recognizing the disputed territory's self-proclaimed independence can "a possible new holocaust" be avoided, he added, referring to the 20th-century Armenian Genocide when about 1.5 million Armenians were killed by Ottoman Turks in 1915-18.
Since 1988, Armenia and Azerbaijan have had an undeclared war over the territory of Nagorno-Karabakh, which lies inside Azerbaijan, but has an ethnic Armenian majority.
After the fall of the Soviet Union, the region proclaimed itself an independent state, leading to waves of conflict and relative stability as well as a broken cease-fire agreement. For decades, the Organization on Security and Cooperation in Europe has been trying to negotiate a permanent resolution to the conflict.
A fresh series of deadly clashes erupted in late September, sparking all sides in the dispute -- Azerbaijan, Armenia and Nagorno-Karabakh -- to increase their mobilization of forces and has drawn in neighboring states, such as Turkey, which has pledged to support Azerbaijan.
Catholicos Karekin said the Armenian church has "set aside half a million dollars to help" those coming into Armenia to escape the conflict, and "we have asked all dioceses and Armenians across the globe to launch fundraising" efforts.
As church leaders, he said, their mission is "to preach God's love among humanity, as well as (highlight) the need for justice and peace by warning when they are in danger."
The international community needs to play a part in resolving the conflict, he said.
"Recognizing the self-proclaimed republic of Nagorno-Karabakh would be enough to solve the problem because it would guarantee the security of its citizens. That is what we are waiting for from our friends and from all those who want to prevent a possible new holocaust," he said.
Catholicos Karekin was able to meet briefly with Pope Francis at the Vatican Sept. 27 -- the day the fighting surged, prompting the Orthodox leader to cut short his visit to Rome.
That same day, after reciting the Angelus, Pope Francis called for the use of dialogue -- not weapons -- to resolve the problems and conflict escalating in the Caucasus region.
"I pray for peace in the Caucasus and I ask the parties in the conflict to make concrete gestures of goodwill and fraternity that can lead to the resolution of problems, not with the use of force and weapons, but through dialogue and negotiations," the pope had said.
He asked people "pray together, in silence, for peace in the Caucasus."