Iran has the world's second-largest proven gas reserves after Russia and it has ambitions to export gas to a host of countries including Armenia, Pakistan and Syria.
 
However, it has failed to become a major international exporter because of a lack of foreign investment and slow progress in exploiting its fields.
 
Despite its export plans, Iran had recently been forced to import gas from neighbouring Turkmenistan because of high domestic consumption.
 
Iran's only gas exports are to Turkey which usually receives around 20 million cubic metres (700 million cubic feet) each day.
 
In January however, Iran had to cut its exports to Turkey for three weeks due to the lack of gas from Turkmenistan and severe cold weather.