The US added 71 entities based in Russia and Belarus to a list that prohibits American firms from doing business with them without getting a government license, tightening restrictions amid the ongoing war in Ukraine. 

Thursday’s action raises the number of parties on the so-called Entity List run by the Commerce Department’s Bureau of Industry and Security to 322 since Russia invaded Ukraine on Feb. 24, the BIS said in a statement. 

The restrictions limit Russia’s ability “to obtain the items and technologies it needs to sustain its military aggression,” Under Secretary of Commerce for Industry and Security Alan Estevez said.  

Commerce spent months prior to Russia’s invasion in late February coordinating potential export controls with global allies to make sure that Moscow wouldn’t simply substitute technology exports from another nation for those that were blocked by the US. The rules are being used to deny Russia access to products used in the defense, aerospace, and maritime sectors.

The department’s efforts have resulted in 37 nations including Japan, Australia as well as the European Union’s member countries joining the US in imposing expansive controls on what they export to Russia. 

Since Feb. 24, when the BIS’s first new rule came into effect, total US exports to Russia have plunged.