Iranian President Hassan Rohani says production has doubled at a massive underwater gas field over the past four years.
Rohani, who is running for reelection in next month's presidential election, said daily Iranian production at the South Pars Gas Field has reached 540 million cubic meters, up from just 240 million when he was elected in 2013.
He said growing production illustrated the success of the "resistance economy," which Supreme Leader Ayatollah Ali Khamenei has emphasized is needed for the country to become self-sufficient and confront threats.
Iranian Oil Minister Bijan Zanganeh said $20 billion has been invested in the offshore gas field over the past decade.
Iran shares the gas field with Qatar, which produces more than 590 million cubic meters per day from the field and plans to increase production by 10 percent by 2022.
Total signed a tentative agreement with Tehran in November for a $4.8 billion project to develop the gas field.