The United States has said for months that North Korean officials have secretly been shipping weapons to Russia, and American officials have vowed to move aggressively to enforce sanctions against people involved in that effort. In December, the Treasury Department announced sanctions against the Wagner group, a Russian paramilitary force with close ties to President Vladimir V. Putin that is accused of serving as an intermediary between Moscow and Pyongyang. North Korea has denied involvement.
The sanctions against Mr. Mkrtychev would cut him off from the U.S. financial system, Mr. Kirby said, adding that “with this new pariah status also comes risks for those who provide support to him, as we will not hesitate to target such malign actors in the future.”
Since the beginning of the Russian invasion, the United States has sought to supply military aid to Ukraine and to isolate institutions and individuals affiliated with Mr. Putin.
“Russia has lost over 9,000 pieces of heavy military equipment since the start of the war, and thanks in part to multilateral sanctions and export controls, Putin has become increasingly desperate to replace them,” Janet L. Yellen, the Treasury secretary, said in a statement announcing the sanctions against Mr. Mkrtychev. “Schemes like the arms deal pursued by this individual show that Putin is turning to suppliers of last resort like Iran and the DPRK,” using an acronym for North Korea.