The U.S. Department of the Treasury imposed new sanctions against Iran on Thursday, targeting the Islamic Republic’s “shadow fleet” used to transport illicit petroleum.

Treasury’s Office of Foreign Assets Control stated that it is designating 29 vessels and their management firms for allegedly facilitating the transfer of hundreds of millions of dollars’ worth of Iranian petroleum products.

“The United States will not allow Iran to have a nuclear weapon,” stated John Hurley, under secretary of the Treasury for terrorism and financial intelligence. “Treasury will continue to deprive the regime of the petroleum revenue it uses to fund its military and weapons programs.”