Iran says it has discovered a gas field reserve with a potential 1.4 trillion cubic meters of natural gas in the Caspian Sea.

The field, located 2,300 feet deep (700 meters), lies within Iran's maritime borders, Oil Minister Rostam Qasemi said on the Ministry of Petroleum's news site.

Iran has 11 trillion cubic meters of proven gas reserves in the Caspian Sea, excluding this latest discovery, the minister said.

Iran is the second-largest oil producing member-nation of the Organization of the Petroleum Exporting Countries. Oil exports account 80 per cent of its public revenues.

According to the BP Statistical Review of World Energy released in June, Iran has 29.61 trillion cubic meters of proven gas reserves. It ranks third in the world on oil reserves and second on gas reserves.

Iran's government is struggling to attract foreign investment to help develop its gas and oil resources amid international economic sanctions. The U.S., United Nations and European Union have imposed sanctions to Iran from developing technology for nuclear weapons. The government says it want nuclear power for civilian purposes.