ANKARA — Turkish Prime Minister Tayyip Erdogan offered what the government said were unprecedented condolences on Wednesday, April 22, to the grandchildren of Armenians killed in World War I by Ottoman soldiers.

In a statement issued on the eve of the 99th anniversary of the deeply contested deaths, Erdogan unexpectedly described the events of 1915 as “inhumane,” using more conciliatory language than has often been the case for Turkish leaders.

Turkish government officials said it was the first time a Turkish prime minister had offered such explicit condolences and described the statement as a historic step, but Erdogan’s words were dismissed as “coldhearted and cynical” by an influential U.S.-based Armenian advocacy group.

The exact nature and scale of what happened during fighting that started in 1915 is highly contentious and continues to sour relations between Turkey and Armenia, a former Soviet republic.

Turkey accepts that many Armenians died in clashes, but denies that up to 1.5 million were killed and that this constituted an act of genocide – a term used by many Western historians and foreign parliaments.

Earlier in April, for example, a U.S. Senate committee resolution branded the massacre of Armenians as “genocide.”

Erdogan’s statement – unusually released in nine different languages including Armenian – repeated previous calls for dialogue between the two countries and the establishment of a historical commission to probe events surrounding the killings.