Iranian President Hassan Rouhani announced on Sunday the discovery of a major oil field with an estimated in-place reserve of 53 billion barrels in southwestern Khuzestan province, Shana reported. At the moment, Iran has some 150 billion barrels of crude oil reserves.
US President Donald Trump reinstated the sanctions against Iran past year after abandoning the landmark 2015 nuclear deal between Iran and six world powers.
Iran ranks as the world's fourth-largest reserve holder of oil, and the second-largest holder of gas reserves, according to the U.S. Energy Information Administration (EIA).
"Despite America's sanctions. Iranian workers have found an oil field with 53 billion barrels of reserves", Rouhani said in a televised speech on Sunday. Figures can vary wildly by country due to differing standards, though it remains a yardstick of comparison among oil-producing nations.
The new oil field could reportedly become Iran's second-largest field, following the one containing 65 billion barrels in Ahvaz city.
The field is 2,400 square kilometres (925 square miles), with the deposit some 80 metres (260 feet) deep, according to the semi-official Tasnim news agency.
The remaining parties to the accord - Britain, China, France, Germany and Russian Federation - have worked to save it by avoiding USA sanctions, but their efforts have so far borne little fruit.
Iran has since gone beyond the deal's stockpile and enrichment limits, as well as started using advanced centrifuges barred by the deal.