The US Congress on Thursday formally recognised the 1915-1917 murder of up to 1.5 million Armenians as genocide.
The Senate's passage of the repeatedly stalled resolution is expected to anger Turkey, which denies there was a genocidal mass murder, insisting the Armenians died as a result of World War I.
In passing the resolution, the United States joined 30 other countries recognising Armenia's claim of genocide, which took place in the final years of the Ottoman empire that was centered in Istanbul.
"It is fitting and appropriate that the Senate stands on the right side of history," said Senator Robert Menendez, who pushed the resolution through.
"I am thankful that this resolution has passed at a time in which there are still survivors of the genocide who will be able to see the Senate acknowledges what they went through," he said, fighting back tears.
Armenian President Nikol Pashinyan called the Senate move "a victory of justice and truth."
The resolution declares that it is US policy "to commemorate the Armenian Genocide through official recognition and remembrance."
It is also policy to "reject efforts to enlist, engage, or otherwise associate the United States government with denial of the Armenian Genocide or any other genocide."
Standing next to Trump at the White House in November, Erdogan warned that "some historical developments and allegations are being used in order to dynamite our reciprocal and bilateral relations."
"Trump's relationship with Erdogan has undercut any serious effort to nudge Turkey in a more constructive direction. As in most other areas of foreign policy at the moment, it's only getting worse."