The U.S. Ambassador to Turkey nominee Jeff Flake said Turkey would face more sanctions if it purchases additional S-400 missiles from Russia.

Responding to questions at a Senate Foreign Relations Committee hearing on Tuesday, Flake criticized Turkey's purchase, saying “any purchase of additional Russian weapons will result in additional sanctions.”

“If confirmed, I will consistently reiterate that disposing of this system is the path to removing CAATSA (Countering America's Adversaries Through Sanctions Act) sanctions,” Flake said.

On Monday, senators warned Turkey on the extension of sanctions in case of additional purchases. The warning came after President Recep Tayyip Erdoğan last week said they still intended to acquire a new batch of S-400 defense systems, despite Washington’s opposition.

Ties between NATO allies Turkey and the U.S. were strained over Ankara’s acquisition of the advanced S-400 Russian air defense system, prompting Washington to remove Turkey from its F-35 Lightning II jet program.

The U.S. argued that the system could be used by Russia to covertly obtain classified details on the Lockheed Martin F-35 jets and is incompatible with NATO systems. Turkey, however, insists that the S-400 would not be integrated into NATO systems and would not pose a threat to the alliance.

Meanwhile, Flake, who had rejected the so-called Armenian genocide during his term as a senator, said he would recognize it if he is appointed as ambassador.

Biden described the killings of Ottoman Armenians during World War I as “genocide” in April.

“We remember the lives of all those who died in the Ottoman-era Armenian genocide and recommit ourselves to preventing such an atrocity from ever again occurring,” Biden said. “And we remember so that we remain ever-vigilant against the corrosive influence of hate in all its forms,” he said.

“We do this not to cast blame but to ensure that what happened is never repeated,” Biden said.

Turkish Foreign Minister Mevlüt Çavuşoğlu was quick to condemn the statement.

“We have nothing to learn from anybody on our own past. Political opportunism is the greatest betrayal to peace and justice. We entirely reject this statement based solely on populism,” Çavuşoğlu said in a Twitter post.

With the acknowledgment, Biden followed through on a campaign promise he made a year ago. Mainly hailing from Ottoman Armenians, Armenians in the U.S. constitute significant communities in East Coast and California.

Turkey’s position on the 1915 events is that the death of Armenians in eastern Anatolia took place when some sided with invading Russians and revolted against Ottoman forces. A subsequent relocation of Armenians resulted in numerous casualties, added by massacres from militaries and militia groups of both sides. The mass arrests of prominent Ottoman Armenian politicians, intellectuals and other community members suspected of links with separatist groups, where those harboring nationalist sentiments and being hostile to Ottoman rule were rounded up in then-capital Istanbul on April 24, 1915, are commemorated as the beginning of later atrocities.

Turkey objects to the presentation of the incidents as “genocide” but describes the 1915 events as a tragedy in which both sides suffered casualties.

Ankara has repeatedly proposed the creation of a joint commission of historians from Turkey and Armenia plus international experts to tackle the issue.

The Senate committee members have until Wednesday to submit more questions to Flake. His nomination will be voted in the senate if approved but the date is unclear.

Flake served in the U.S. Senate for Arizona from 2013 to 2019 and in the U.S. House from 2001 to 2013. Flake retired from the Senate at the end of his term in 2019, saying he was out of step with the Republican Party in the era of former President Donald Trump.

He later wrote a book, "Conscience of a Conservative,” that was a critique of Trump.

"With this nomination, the Biden Administration reaffirms the best tradition of American foreign policy and diplomacy: The credo that partisan politics should stop at the water’s edge. U.S. foreign policy can and should be bipartisan,” Flake said in a statement. "That is my belief as well, and my commitment,” he noted.

Flake was one of more than two dozen former Republican deputies to announce their support for "Republicans for Biden.” Former Reps. Charlie Dent of Pennsylvania, Jim Greenwood of Pennsylvania and Jim Leach of Iowa and Sen. John Warner of Virginia, who died in May, are among the former Republican lawmakers who endorsed Biden last year.

The list of disagreements is unusually long for the two NATO allies: There is U.S. support for YPG terrorists, the PKK's Syrian offshoot in Syria, as well as Turkey’s purchase of the Russian S-400 air defense system. And in April, Biden infuriated Ankara by declaring that the 1915 events regarding the Ottoman Armenians during World War I as "genocide.”