The U.S. Treasury has announced sanctions against two Chinese makers of drone engines and parts that the Biden administration says directly helped Russia build long-range attack drones used in the war in Ukraine.

The U.S. Treasury Department Thursday sanctioned three organizations and one person for aiding development and production for Russian Garpiya drones used to attack Ukraine.

China has forged closer ties with Russia since the invasion of Ukraine, but it has repeatedly denied supplying weapons.

The United States on Thursday sanctioned two Chinese companies and a Russian affiliate involved in making and shipping attack drones and warned the two countries to halt cooperation boosting the Ukraine war effort.

Limbach and Redlepus — have been working in tandem with IEMZ Kupol, a subsidiary of the Kremlin-owned weapons company Almaz-Antey, to create the drones, the U.S. Treasury Department's Office of Foreign Assets Control (OFAC) said in a statement.