The list includes 33 Russian defense and six intelligence sector organizations, the Federal Security Service and Foreign Intelligence Service among them.

In addition to the already-blacklisted arms maker Kalashnikov Concern, the U.S. designation includes Russia’s state arms exporter Rosoboronexport and massive state-owned defense conglomerate Rostec, which are also under U.S. sanctions.

American companies would be prohibited from doing “significant” business with companies on the list, beginning late January 2018.

Nauert explained the three-week delay with producing the list by saying it was the State Department’s effort to help U.S. and allied firms avoid running afoul of the possible sanctions.

“Part of this is to say to the companies – and many of these are big multinational companies – put them on alert that these are the types of things that they can no longer do business with.”

In anticipation of the potential sanctions, Russia is reportedly looking to designate a bank to exclusively service the country’s defense industry by year-end, the Kommersant business daily reported.

Shortly after the list was released, the Foreign Policy magazine cited congressional sources as saying that U.S. Secretary of State Rex Tillerson had dissolved an office that oversees sanctions policy. A mid-level State Department manager is now reportedly in charge of coordinating U.S. sanctions.