Turkey’s foreign minister suggested Wednesday that the United States could be barred from using two strategic air bases in retaliation to possible US sanctions against his country, the state-run Anadolu Agency reported.

Mevlut Cavusoglu comments came amid reports that US lawmakers had agreed on a defense bill that also includes calls to sanction Turkey over its decision to proceed with the purchase and deployment of Russian-made S-400 missile defense systems.

“In the event of a decision to sanction Turkey, the Incirlik and Kurecik air bases can be brought to the agenda,” Anadolu quoted Cavusoglu as saying.

He said: “Congress members must understand that it is not possible to get anywhere with sanctions.”

Incirlik air base in southern Turkey has been a main base for US operations in the Middle East and more recently in the fight against the Daesh group in Syria and Iraq, while Kurecik, in eastern Turkey, is a key NATO base.

Turkey’s decision to proceed with the purchase of the Russian system has added to growing tensions between the two NATO allies. Washington says the Russian system poses a threat to NATO and has removed Turkey from the US-led F-35 stealth fighter jet program.

Tensions were raised further after Turkey launched an incursion into northeastern Syria to drive away Syrian Kurdish forces that had partnered with the US in the fight against the Daesh group. Turkey considers the Kurdish fighters as terrorists because of their links to outlawed Kurdish rebels fighting inside Turkey.

-AP