The United States Department of the Treasury has added three Russian companies to its sanctions list for their supposed links to Iran's military aircraft production.

The three companies are Delta-Aero LLC, JSC SPE Aerosila, and JSC Star, which in Washington's opinion aided the Iran Aircraft Manufacturing Industrial Company (HESA) sanctioned by the United States, the Treasury's Office for Foreign Assets Control (OFAC) said in a document.

The United States also sanctioned seven individuals and one entity based in Iran, China and Turkey "in connection with Iran's unmanned aerial vehicle (UAV) and military aircraft development," it said. The U.S. thinks that they "facilitated shipments and financial transactions in support of the [HESA's] UAV and military aircraft production, procurement, and maintenance activities," the OFAC said.