The U.S. imposed sanctions against nine companies, including Iranian companies, linked to Iran's petrochemical activities, according to the U.S. Treasury Department's website.

The U.S. Treasury Department's Office of Foreign Assets Control today imposed sanctions on nine entities in various jurisdictions that played a critical role in the production, sale and shipment of hundreds of millions of dollars worth of Iranian petrochemical products and oil to buyers in Asia, the Treasury Department said in a statement on its website.

The new sanctions list includes six Iranian companies and three firms based in Malaysia and Singapore.

Among the sanctioned companies is Amir Kabir Petrochemical Company, Iran's largest producer of polyethylene.