US sanctions Turkey over purchase of Russia's S-400 missile system

President Trump placed sanctions on Turkey for purchasing a Russian anti-aircraft defense missile system, delivering a long-awaited punishment in a controversy that threatens the unity of NATO.

“We engaged in months and months of diplomacy with the Turkish government at every level to help Turkey find an off-ramp from the procurement of the S-400 system while still ensuring its legitimate national security needs are met,” State Department Deputy Assistant Secretary Matthew Palmer, a senior member of the Bureau of European and Eurasian Affairs, told reporters Monday. “Imposing sanctions on a NATO ally is not something we take lightly.”