The USA has added seven companies involved in the transportation and sale of Iranian oil to its sanctions list, according to the US Treasury Department's statement.
Restrictive measures will target Iraqi businessman Walid Khaled Hamid al-Samarrai, who owns a network of companies operating vessels used to sell Iranian oil on world markets.
The statement says that these companies mixed Iranian oil with Iraqi crude and sold it as exclusively Iraqi. According to estimates, this scheme allowed Iran and its partners to earn approximately $300 million annually.
Nine ships flying the Liberian flag were also sanctioned.