The price for Brent crude oil has fallen below $28 a barrel, its lowest point since 2003, amid concerns that the lifting of sanctions against Iran will boost the global oversupply of oil.
Tehran has already announced plans to increase its crude oil exports by about 500,000 barrels a day, which is likely to further increase the oil supply glut that has brought oil prices down by about 25 percent since the start of the year.
Iran currently produces 2.8 million barrels per day and exports just over one million barrels per day.
During the weekend, the United States and the European Union ended economic sanctions linked to Iran's nuclear program after the International Atomic Energy Agency certified that Tehran had fulfilled its obligations under a nuclear deal reached in July with world powers.