The US House of Representatives took the historic step of passing a resolution officially recognising the "Armenian genocide," a move sure to anger Turkey amid already-heightened tensions between the countries.
Cheers and applause erupted when the chamber voted 405 to 11 in support of the symbolic resolution "affirming the United States record on the Armenian Genocide," a first for the US congress, where similar measures with such direct language have been introduced for decades but never passed.
House Speaker Nancy Pelosi said she was honoured to join her colleagues "in solemn remembrance of one of the great atrocities of the 20th century: the systematic murder of more than 1.5 million Armenian men, women and children by the Ottoman Empire."
Meanwhile, Turkey rejected the measure, warning it risks harming ties "at an extremely fragile time" for international and regional security.
"As a meaningless political step, its sole addressees are the Armenian lobby and anti Turkey groups," the foreign ministry said in a statement.
"We believe that American friends of Turkey who support the continuation of the alliance and friendly relations will question this grave mistake and those who are responsible will be judged by the conscience of the American people," it added.
The Armenians say the mass killings of their people from 1915 to 1917 amounted to genocide, a claim recognised by some 30 countries. Turkey strongly denies the accusation of genocide.
But Ms Pelosi, the top Democrat in the House of Representative, delivered bold remarks to the House, saying the truth of the "staggering crime" has been denied too often.
"Today, let us clearly state the facts on the floor of this House to be etched forever into the Congressional Record: the barbarism committed against the Armenian people was a genocide."
The government measure passed three weeks after Turkey invaded northeastern Syria and launched a broad assault on Kurdish-controlled areas that was made possible by the withdrawal of US troops.
This action is the second penalty issued by US politicians against Turkey, with the genocide measure passing alongside a bill that places sanctions on Turkey for its incursion.
That bipartisan measure imposes sanctions on senior Turkish officials involved in the decision to launch the invasion and a Turkish bank with ties to President Recep Tayyip Erdogan, and requires the Trump Administration to penalise Turkey's procurement of a Russian-made missile-defense system.
Former vice president Joe Biden, a 2020 Democratic White House hopeful, welcomed the Armenia vote, tweeting that "by acknowledging this genocide we honor the memory of its victims and vow: never again."
I welcome the House's passage of H Res 296, which recognizes and condemns the Armenian Genocide of 1915-23. By acknowledging this genocide we honor the memory of its victims and vow: never again.— Joe Biden (@JoeBiden) October 29, 2019
It was also welcomed outside the political realm. US television reality star Kim Kardashian, who has Armenian ancestry, tweeted about the vote to her 62 million followers.
"This is personal for me, and millions of Armenians who descended from genocide survivors," she said.
According to estimates, there are between 500,000 and 1.5 million Americans of Armenian origin.