The United States Thursday imposed sanctions on an Iranian company for coordinating transport of Iranian drones to Russia as well as 3 companies involved in their production.

The United States accuses Iran of supplying drones to Russia for use in its war in Ukraine.

The US Treasury Department in a statement said it designated Tehran-based Safiran Airport Services, accusing it of coordinating Russian military flights between Iran and Russia, including those associated with transporting drones, personnel and related equipment.

The Treasury also designated Paravar Pars Company, Design and Manufacturing of Aircraft Engines and Baharestan Kish Company, accusing them of being involved in the research, development, production and procurement of Iranian drones.

The Treasury singled out Paravar Pars Company for involvement in the reverse engineering of US and Israeli-made drones, without specifying which models.

Reuters has reported that some of Iran's drones are based on unmanned aircraft from other countries, including an aerial US RQ-170 Sentinel reconnaissance drone captured in 2011. Also designated was Baharestan Kish Company’s managing director and a member of its board of directors, Rahmatollah Heidari.

Russia most likely planned to acquire hundreds of Mohajer-6 and Shahed-series unmanned aerial vehicles (UAVs), a US official had said.

On Thursday, undersecretary of the Treasury for terrorism and financial intelligence, Brian Nelson, said in a statement, "The United States is committed to strictly enforcing our sanctions against both Russia and Iran and holding accountable Iran and those supporting Russia’s war of aggression against Ukraine."

Thursday's sanctions come as indirect talks between Iran and the United States have made only stuttering progress towards reviving a 2015 deal.

Reporting by Reuters