The U.S. Senate has unanimously passed a resolution recognizing the mass killing of Armenians in the Ottoman Empire a century ago as genocide, a move Armenia’s prime minister hailed as a "victory of justice and truth."



The resolution, pushed by New Jersey Democratic Senator Bob Menendez, recognizes the killing of an estimated 1.5 million Armenians from 1915-1923 by the Ottoman Empire.



“By passing my Armenian Genocide resolution, the Senate finally stood up to confirm history: What happened from 1915 to 1923 was -- most assuredly -- genocide. There is no other word for it. There is no euphemism. There is no avoiding it,” said Menendez following the December 12 vote.



Republican Senator Ted Cruz of Texas said the Senate "finally took a stand and spoke the truth -- spoke the truth to darkness, spoke truth to evil, spoke truth to murder, spoke truth to genocide -- and finally honored the 1.5 million innocent lives lost.”



Armenian Prime Minister Nikol Pashinian hailed the vote in a post on Twitter.



"On behalf of the #Armenian people worldwide, I express our profound appreciation to the Senate for this landmark legislation," Pashinian wrote.

The Democrat-led House of Representatives overwhelmingly passed a similar nonbinding resolution in late October.



"History will note these resolutions as irresponsible and irrational actions by some members of the US Congress against Turkey," Turkey's presidential communications director Fahrettin Altun tweeted. "They will go down in history as the responsible party for causing a long lasting damage between two nations."

The vote in the Senate comes after the upper chamber of Congress had three attempts to pass the measure in recent weeks blocked by individual Republican senators.



Congressional aides said the White House did not want the legislation to move ahead while it was negotiating with Ankara on sensitive issues such as Turkey's offensive against Kurdish fighters in northern Syria and the NATO ally's purchase of an S-400 missile-defense system from Russia, which could provoke U.S. sanctions.



WATCH: In October, Armenians React To Genocide Resolution In The U.S. House of Representatives

During and immediately after World War I, Ottoman Turks killed or deported as many as 1.5 million Armenians -- a Christian minority in the predominately Muslim empire. Many historians and some other nations consider the killings genocide.



Turkey, a NATO member, objects to the use of the word genocide to describe the killings. Ankara claims the deaths were a result of civil strife rather than a planned Ottoman government effort to annihilate Armenians. Turkey also claims fewer Armenians died than has been reported.

At least 23 countries, including France and Germany, officially recognized the mass slaughter and deportation as genocide.



Aram Hamparian, the executive director of the Washington-based Armenian National Committee of America, hailed the vote in the Senate as long overdue.



“What is special about this resolution is that it locks in recognition and very explicitly rejects denial and those are the two key clauses,” Hamparian told RFE/RL.



"Armenian-Americans see this as an important step toward putting America on the right side of this issue,” he added, while Ankara will “find itself increasingly isolated since the U.S. is stepping away.”



"Like many Armenians, I grew up hearing of the genocide’s horrors," Representative Jackie Speier (Democrat-California), co-chair of the Armenian Caucus, wrote in a tweet. "This eases some of that pain & America has sent a clear message – perpetrators will be held accountable."



With reporting by AP and Reuters