Calling the decision announced on Monday “the right first step in the right direction,’’ Lankford accused Turkey failing to behave like a NATO ally.

“They continue to compromise our national security by engaging with Russia,’’ Lankford said on Twitter.

“Today’s action further demonstrates to President Erdogan that what they’re doing is unacceptable. The United States should also impose targeted sanctions on officials and entities responsible for the purchase and use of the S-400 if Turkey does not reverse course,” he added.

In 2018, Lankford introduced a bill to thwart the transfer of the F35 Joint Strike fighter aircrafts to Turkey. He managed to remove Turkey from participation in the F35 program in the initial Fiscal Year 2019 (FY19) National Defense Authorization Act (NDAA), Congress’s annual defense bill.

In 2019, the Pentagon revealed it would suspend deliveries of the F35 to Turkey after Lankford and his colleagues introduced another bill that would prohibit the transfer of the F-35 aircraft to Turkey if they accepted delivery of Russia’s S-400 air defense system.

The Wall Street Journal recently published an op-ed penned by Lankford who endorsed the use of CAATSA sanctions as a diplomatic tool to warn Turkey about its engagement with Russia.

The United States says Russia's S-400 missile system is incompatible with NATO technology and a threat to the Euro-Atlantic alliance. The move has been condemned by officials in Turkey and Russia.

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