The Trump administration on Monday unveiled limited sanctions on Turkey in response to the NATO ally’s purchase of Russia’s S-400 missile defense system last year.

The sanctions include a ban on US goods and technology exports to Turkey’s defense procurement agency, or SSB, and specifically target the body’s chief Ismail Demir, vice president Faruk Yegit, head of air defense Serhat Gencoglu and program manager for Turkey’s regional air defense Mustafa Alper Deniz. All four have also been hit with asset freezes and visa restrictions.

“The United States has made clear to Turkey at the highest levels and on numerous occasions that its purchase of the S-400 system would endanger the security of US military technology and personnel and would provide substantial funds to Russia's defense sector, as well as Russian access to the Turkish armed forces and defense industry,” Christopher Ford, the State Department’s top nonproliferation official, told reporters on Monday.

Turkey’s Foreign Ministry condemned the decision as “completely senseless,” warning that Ankara will “retaliate in a manner and timing it deems appropriate.”