U.S. Senator Lindsey Graham blocked a resolution that would have formally recognized the so-called Armenian genocide.
Graham objected to passing the resolution in the Senate, saying senators shouldn't "sugarcoat history or try to rewrite it."
Under the Senate's rules, any one senator can ask for consent to pass a bill or resolution, but any one senator can block it.
Graham's objection came hours after he took part in a White House meeting with U.S. President Donald Trump and Turkish President Recep Tayyip Erdogan.
"I just met with President Erdoğan and President Trump about the problems we face in Syria by the military incursion by Turkey. I do hope that Turkey and Armenia can come together and deal with this problem," the Hill cited Graham as saying.
Earlier, Senator Robert Menendez asked for consent to pass the resolution that would have provided "official recognition and remembrance" of the Armenian genocide.