The U.S. Department of Treasury on Monday sanctioned a Russian-born South African national for links to a previously-designated Singaporean company involved in North Korea’s oil trade.

Vladlen Amtchentsev was reported by the Treasury to have acted on behalf of Velmur Management, which was previously sanctioned by the department’s Office of Foreign Assets Control (OFAC) for its role in delivering oil products to the DPRK.

“North Korea depends upon the help of criminals and illicit actors to raise and transfer funds,” Treasury Secretary Steven Mnuchin said in a press release accompanying the designation.

“As part of our commitment to the final,