Russian S-400 anti-missile system
Russian S-400 anti-missile systemReuters

A US official warned on Wednesday that Turkey faced a risk of sanctions after it defiantly tested Russia's S-400 air defense system, AFP reports.

"That risk is very real because they... continue to pursue the S-400," R. Clarke Cooper, the top State Department official in charge of arms sales, was quoted as having said.

"And, of course, with the testing of it, sanctions is very much something that is on the table," he told a small group of reporters.

Turkey recently confirmed the first test of the S-400 despite months of warnings from the United States that the system was incompatible with membership in NATO and could help Russia hone skills in shooting down Western fighter jets.

Turkey signed a contract with Russia in 2017 to purchase the S-400 system, raising the ire of the United States.

A law passed overwhelmingly by Congress that year lays out sanctions against nations that buy significant quantities of arms from US adversaries including Russia.

The first parts of the S-400 air defense system were delivered to Turkey in July of 2019. Russia then delivered a second battery of S-400s a month later.

The US has already kicked out Turkey from its elite F-35 fighter-jet program after it bought the S-400 system.

Cooper said the US had set a red line of Turkey not activating the S-400.

Even after the test, he hoped that Turkey would "walk back from operationalizing" the system.

"Put it away, decommission it, just do not integrate it and make it operable," he said, adding, "We certainly are working to make sure that Turkey remains in the West. This is something that's important not only to the United States, but to the overall alliance."

Turkish President Recep Tayyip Erdogan in a speech Sunday hit back at the threat of sanctions, accusing the US of treating his country like a "tribal state."

Turkey has repeatedly made clear it will use the Russian system despite US threats of sanctions.