The Countering America’s Adversaries Through Sanctions Act of 2017 was designed to bind Trump to ensure that he would not lift Russia's sanctions. On December 14, 2020, Turkey's Defense Industry presidency was sanctioned, based on the purchase of an S-400 air and missile defense system from Russia. "Today's action sends a clear signal that the United States will fully implement CAATSA Section 231 and will not tolerate significant transactions with Russia's defense and intelligence sectors," US Secretary of State Mike Pompeo said in a statement. "I also urge Turkey to resolve the S-400 problem immediately in coordination with the United States. Turkey is a valued ally and an important regional security partner for the United States, and we seek to continue our decades-long history of productive defense-sector cooperation by removing the obstacle of Turkey's S-400 possession as soon as possible," he added. The US also removed Turkey from its F-35 program, one of America's most high-level fighter aircrafts, stating that the S-400 will endanger the F-35 and damage NATO's “ability to cooperate militarily.” Erdogan condemned the sanctions. "We expect support from our NATO ally, the United States, in our fight against terrorist organizations and the forces that have accounted for our region, not sanctions," the president said.
