The U.S. State Department has imposed sanctions on three Russian entities and one individual for involvement in the transfer and testing of North Korea’s ballistic missiles for Russia’s use against Ukraine.

U.S. Secretary of State Antony Blinken announced the move in a statement on Thursday, saying that Pyongyang’s transfer of ballistic missiles to Moscow supports its war of aggression, increases the suffering of the Ukrainian people, and undermines the global nonproliferation regime.

Blinken said that the U.S. continues to closely monitor any support from Russia to the North in return for the weapons.

He added that Washington will use all available tools to designate and expose individuals and entities involved in arms transfers between the two nations, warning that there will be no hesitation to take further action.