The United States recognizes the 1915 massacre of as many as 1.5 million Armenians by the Ottoman Empire as genocide, President Joe Biden said in a statement on Saturday.
The announcement came on the day that Armenians worldwide mark Genocide Remembrance 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," said Biden.
"And we remember, so that we remain ever-vigilant against the corrosive influence of hate in all its forms ... The American people honor all those Armenians who perished in the genocide that began 106 years ago today ... We affirm the history. We do this not to cast blame but to ensure that what happened is never repeated," he added.
How did Turkey respond?
Minutes after Biden's declaration, Turkey responded by saying it "entirely" rejects the label. Later Saturday, Turkey's Foreign Ministry said it had summoned the US ambassador to Turkey to convey Ankara's "rejection" of the genocide designation.
"We have nothing to learn from anybody on our own past. Political opportunism is the greatest betrayal to peace and justice," Turkish Foreign Minister Mevlut Cavusoglu said on Twitter. "We entirely reject this statement based solely on populism."
Turkish presidential spokesman Ibrahim Kalin later said Biden should look at recent American history before criticizing others.
"We strongly condemn and reject the US president's remarks, which only repeat the accusations of those whose sole agenda is enmity towards our country," Kalin said. "We advise the US President to look at (his country's) own past and present."
Armenians have long referred to the mass killings during World War I as the Armenian genocide.
Turkey denies a genocide had taken place, and the United States has refrained from using the term until today. DW Washington Bureau Chief Ines Pohl noted that Biden's predecessors had been "wary of damaging ties with Turkey, a key regional ally."
Biden's declaration fulfilled a campaign pledge to describe the killings as a deliberate attempt to wipe out the Armenian people.
But the move could spell problems for US ties with the Turkish government, which is a member of the NATO military alliance.
Faik Oztrak, a spokesman for the main opposition Republican People's Party, sided with the government in hitting out at the statement made by the White House.
He was quoted by the Reuters news agency as saying that the move "will open wounds that will be difficult to repair not only on US-Turkey ties but also on a potential compromise between the people of Armenia and Turkey."
What is Armenia's stance?
Armenian Prime Minister Nikol Pashinyan thanked Biden in a post on Facebook for "the powerful step towards justice and invaluable support for the descendants of the Armenian genocide victims."
In Armenia on Saturday, people streamed to the hilltop complex in Yerevan, the capital, that memorializes the victims.
Speaking at the memorial before Biden issued his proclamation, Armenian Deputy Foreign Minister Avet Adonts said a US president using the term genocide would "serve as an example for the rest of the civilized world."
jf/dj (AFP, AP)