"Discussion over Turkish investment in the development of phases 22, 23 and 24 of Iran's South Pars gas field was a high on the agenda of talks between the two sides," the Iranian oil minister said.
Ankara and Tehran in 2008 signed an agreement where the Turkish Petroleum Corp. would produce 720 billion cubic feet of natural gas each year from three development phases at South Pars.
Kazemi said following the meeting that Ankara would invest at least $3.5 billion to help Iran develop the South Pars field.
Iran aims to deliver its lucrative natural gas reserves to European markets through Turkish territory. Tehran insists its gas would help meet the reserve obligations for the lauded Nabucco gas pipeline, though Western officials said that is out of the question.
Iran says the South Pars gas field holds about 8 percent of the world's total gas reserves.