An Argentine judge says "the Turkish state committed the crime of genocide against the Armenian people" between 1915 and 1923.
The ruling Friday also says Turkey should help an Armenian descendant living in Argentina learn the fate of more than 50 of his relatives who disappeared nearly a century ago.
Many international experts say the killing of up to 1.5 million Armenians by Ottoman Turks around the time of World War I was genocide. Turkey maintains that far fewer died and due to civil war and unrest, rather than genocide.
The Turkish Embassy in Buenos Aires has not immediately responded to a request for comment.
Judge Norberto Oyarbide says his ruling is "declarative" only, with no value other than the truth.