Kürecik Radar Station a NATO military installation located in southeastern Turkey

Turkey is upping the ante with threats to retaliate against the US if it imposes sanctions on Ankara for its purchase of a Russian missile system.

Turkish President Recep Tayyip Erdogan on Sunday threatened to close two strategic military bases used by the United States in Turkey if Washington imposes sanctions on Ankara for buying a Russian missile system.

"If necessary, we'll close Incirlik and also Kurecik," Turkish President Recep Tayyip Erdogan told broadcaster A Haber on Sunday, referring to two military bases used by the United States. "If the threat of sanctions is implemented against us, we'll respond to them in the framework of reciprocity."

Incirlik is an air base in southern Turkey that has played a major role in US military operations in the Middle East and Afghanistan, and more recently against the "Islamic State" (IS) group in Syria and Iraq. The US military also stores around 50 B-61 gravity nuclear bombs at the base.

Kurecik in eastern Turkey houses a NATO radar station.

Earlier this week, Turkish Foreign Minister Mevlut Cavusoglu also brought up the issue of closing the two bases to the US if Washington imposes sanctions.