The entities and vessels sanctioned on Tuesday "play a critical role in transporting illicit Iranian petroleum to foreign markets," according to a statement by the US Department of Treasury.
The statement said petroleum revenues provide Tehran with the resources to fund its nuclear program, develop advanced drones and missiles, and provide ongoing financial and material support for the activities of its regional proxies.
The new sanctions are being imposed a few weeks before the inauguration of President-elect Donald Trump. The Biden administration has long been criticized by Republicans and Iranian opposition groups for lack enforcement of the oil sanctions in place against the Islamic Republic.
Senator Jim Risch, a Ranking Member of the US Senate Foreign Relations Committee, said the Biden admin is "late on nearly every requirement under the SHIP Act", which targets Tehran’s oil exports in defiance of US sanctions.
The previous Trump administration imposed his so-called maximum pressure against Tehran, reducing its oil exports to 200,000 bpd, according to assessments based on tanker tracking. However, Iran's oil exports rose to over 2.2 million barrels a day in August 2023, mostly to China and through the so-called "shadow fleet".