"Without unity among members of OPEC, it is meaningless to plan cooperation between OPEC and non-OPEC countries," Zanganeh said in a report by Shana, the Iranian oil ministry news service, before leaving Tehran to attend OPEC meeting in Vienna.
Tehran has in the past objected to policies put forward by its regional arch-rival Saudi Arabia, saying Riyadh was too close to the United States.
"Iran supports cooperation with non-OPEC states, but as long as some members of OPEC are hostile against other members, like Iran, OPEC's understandings with non-OPEC states are meaningless and there is no room for cooperation," Zanganeh said.
OPEC and its allies look set to extend oil supply cuts at least until the end of 2019 as Iraq joined top producers Saudi Arabia and Russia on Sunday in endorsing a policy aimed at propping up the price of crude amid a weakening global economy.OPEC members meet on July 1 in Vienna followed by a meeting with non-OPEC states on July 2, switching from previously agreed dates of June 25-26.