President Joe Biden became the first US president to formally refer to atrocities committed against Armenians as a “genocide” on Saturday, 106 years after the 1915 start of an eight-year-long campaign of ethnic cleansing carried out by the Ottoman Empire that left between 1 million and 1.5 million Armenians dead.

Previous presidents have refrained from using the word “genocide” in connection with the mass atrocities committed against the Armenian people in the early 20th century, and Turkey categorically denies that a genocide took place. So Biden’s declaration marks a major break from precedent, and could signal an increase in tensions with Turkey, a longtime US and NATO ally.

“Each year on this day, we remember the lives of all those who died in the Ottoman-era Armenian genocide and recommit ourselves to preventing such an atrocity from ever again occurring,” Biden said in a statement Saturday. “And we remember so that we remain ever-vigilant against the corrosive influence of hate in all its forms.”