President Joe Biden on Saturday defied decades of Turkish pressure and recognized the mass killings of Armenians by the Ottoman Empire as genocide, leading Ankara to summon the US ambassador.

Blinken noted that Biden told Turkish President Recep Tayyip Erdogan by telephone of the decision so there would be "no surprises" and agreed to meet him in June on the sidelines of a NATO summit.

"We owe Turkey the respect of stating our disagreements clearly, directly, honestly, just as we expect and anticipate the same from Turkey," Blinken told a roundtable on international press freedom in response to a question from a Turkish journalist.

"I very much hope that we can find a positive way forward," Blinken said, calling on the two countries to "work together and deepen our cooperation."

Biden had previously given a cold shoulder to Erdogan, whom he has called an autocrat, and relations were already sour over NATO member Turkey's purchase of S-400 air defense systems from Russia, the alliance's chief adversary.

The United States has repeatedly warned Turkey to dump the S-400s, with a law passed by Congress in 2017 requiring sanctions against other countries over "significant" purchases of Russian weapons.

"We are bound to the so-called CAATSA legislation that I'm sure you know well and we will follow the law going forward," Blinken said.

He said that any sanctions would be in addition to measures imposed by former president Donald Trump in December that narrowly targeted Turkey's military procurement agency.

Blinken said the air system provided Russia with "revenue, access and influence."

"The purchase of the S-400s is dangerous to the security of the United States and allied military technology, personnel as well, and it undermines the cohesion of the alliance," he said.