WASHINGTON — President Joe Biden on Saturday made good on a campaign pledge when he acknowledged that the mass slaughter of Armenians during the Ottoman era that started 106 years ago was genocide.

U.S. presidents have been reluctant to use the word genocide — a powerful, particular term invented in 1944 after the Holocaust by Raphael Lemkin, a Polish-Jewish lawyer who moved to the U.S. two years before.

Former President Barack Obama promised, but never delivered on calling the killings genocide, unwilling to antagonize Turkey — a nation born out of the Ottoman Empire — which has denied that what took place was genocide.

Ex-President Donald Trump was close to Turkish President Recep Tayyip Erdogan and continued the U.S. government policy of not recognizing the murders as genocide in order to not alienate Turkey, a NATO ally.

Biden was the first president to say the systematic atrocities suffered by Armenians was genocide, and he did so on Armenian Remembrance Day.

“Beginning on April 24, 1915, with the arrest of Armenian intellectuals and community leaders in Constantinople by Ottoman authorities, one and a half million Armenians were deported, massacred, or marched to their deaths in a campaign of extermination,” Biden said in his statement.

Lemkin’s quest to find a new word to describe the Nazi atrocities is detailed in “A Problem From Hell: America and the Age of Genocide,” which earned a 2003 Pulitzer Prize for its author, Samantha Power.

Power, who went on to be Obama’s United Nations Ambassador — and before that director of Obama’s Atrocity Prevention Board — is Biden’s nominee to be the administrator of the United States Agency for International Development.

Lemkin was determined to coin a new word after listening to British Prime Minister Winston Churchill’s Aug. 24, 1941, radio address. Talking about Hitler’s savagery, Churchill said, “There has never been methodical, merciless butchery on such a scale, or approaching such a scale. ….We are in the presence of a crime without a name.”

Lemkin realized that Hitler’s destruction of a people — in contrast to deaths caused by conventional warfare between nations — needed its own name.

Lemkin, wrote Power, “hunted for a term that would describe assaults on all aspects of nationhood — physical, biological, political, social, cultural, economic and religious. He wanted to connote not only full-scale extermination but also Hitler’s other means of destruction: mass deportation, the lowering of the birthrate by separating men from women, economic exploitation, progressive starvation, and the suppression of intelligentsia who served as national leaders.”

As he search for the right word, Lemkin looked to “coinages he admired,” Power recounted. “Of particular interest to Lemkin were the reflections of George Eastman, who said he settled upon “Kodak” as the name for his new camera because: First. It is short. Second. It is not capable of mispronunciation. Third. It does not resemble anything in the art and cannot be associated with anything in the art except Kodak.”

Lemkin had a more difficult challenge than Eastman. The word Lemkin coined had to “chill listeners and invite immediate condemnation.”

He created the word genocide. He fused the Greek word “genos,” which means a race or a tribe, with the Latin word for killing, “cide.”

The United State Holocaust Memorial Museum defines genocide as “an internationally recognized crime where acts are committed with the intent to destroy, in whole or in part, a national, ethnic, racial, or religious group.”

The House and Senate approved resolutions in 2019 referencing the Armenian genocide. State lawmakers in the Illinois General Assembly members affirmed the genocide in resolutions passed six years ago. Last month, Gov. J.B. Pritzker issued a proclamation underscoring that teaching about the Armenian genocide is part of the mission of state-mandated Holocaust education.

Reuters reported on Sunday that Erdogan’s spokesman, Ibrahim Kalin, said calling the deaths of Armenians at the hands of the Ottoman Empire a genocide is “simply outrageous” and the U.S. should expect “there will be a reaction of different forms and kinds and degrees.”

By the end of this week, Biden will have marked his 100^th day in office. Biden will deliver an address to a joint session of Congress on Wednesday to highlight his 100-day record. His declaration of the genocide in Armenia is an important promise kept.