The United States imposed new sanctions Thursday on Iran-linked shipping and petrochemical companies, including two shipping firms based in China.

The sanctions also target 20 shipping vessels linked to firms in China, Vietnam and the United Arab Emirates, the Treasury Department's website showed.

The Biden administration has accelerated the imposition of sanctions on Iran since last September when antigovernment protests were met by a brutal government response. Iran’s weapons supply to Russia have also led to sanctions by the US, the European Union and the United Kingdom.

Iran has been shipping oil and oil products despite US sanctions, imposed since 2018, to China and other buyers, using clandestine methods. Third parties involved in sanctions violations are subject to US punitive measures.

The website did provide details on the new sanctions. A Treasury spokesperson referred questions to the State Department, which did not immediately respond to a request for comment.

The sanctions were issued under a 2018 U.S. executive order that restored sanctions targeting Iran's oil, banking and transportation sectors.

The Treasury Department issued a general license authorizing limited transactions with the sanctioned vessels under what it called a "wind-down" period through June 29, a document on its website showed.

Report by Reuters