Thousands of people packed Times Square on Sunday to demand the U.S. government recognize the deaths of up to 1.5 million Armenians during World War I as genocide.
The rally marked the centennial of the killings under the Ottoman Empire -- today's Turkey.
"It's humanity's issue. It's not just about Armenian people; history continues to repeat itself," said Nancy Guetssoyan, 28, of Weehawken, New Jersey. "The U.S. government has not declared it a genocide because they're allies with Turkey."
The age-old international dispute over the Armenian deaths focuses on the interpretation of one word: genocide.
Pope Francis recently called the killings genocide, a view widely shared by scholars.
Turkey, however, denies that the deaths constituted genocide, saying the toll has been inflated and that those killed were victims of civil war and unrest. Last week, Turkish President Recep Tayyip Erdogan insisted that his nation's ancestors never committed genocide.
Friday marked the anniversary of the 1915 starting date of what Armenians say were the executions of hundreds of intellectuals and community leaders in Constantinople, now Istanbul. The killings continued during and after World War I, accompanied by forced labor and deportation of women, children and the elderly, Armenians allege.
Ethnic Armenians living in the United States are pushing for a formal vote in Congress that would classify the killings as genocide.
Sen. Charles Schumer, D-NY, spoke to the crowd on Sunday, saying, "I stand with you in making sure the deniers are not given any place under the sun."
Rally speakers included several Jewish leaders as well as Taner Akcam, a Turkish-born scholar who supports the Armenian cause as a professor at Clark University, in Worcester, Massachusetts.
"It is very troubling to see that the United States has still not recognized the Armenian genocide," he said, adding that the justification is the crucial role of Turkey in U.S. security strategy.
The New York rally was sponsored by the Armenian Genocide Centennial Committee of America.