That's according to an unidentified government official talking on Thursday to Reuters.
OPEC invited Iraq to its 24 September meeting in Vienna earlier this week. It will be the first time an Iraqi delegation has attended one of the cartel’s meetings since the country was occupied by US soldiers.
The official, who declined to be named, said Venezuelan President Hugo Chavez remarked at a private luncheon on Wednesday that he would not recognise missives from a “foreign” occupier in Iraq.
Venezuela's oil minister Rafael Ramirez and other OPEC leaders had said they would only welcome delegates from a government recognized by the United Nations.
Most OPEC members softened their stance after Arab League foreign ministers let the Governing Council take Iraq's vacant seat at talks last week in Cairo. Seven OPEC members are in the Arab League.
It was not clear if this would affect the proceedings of the OPEC meeting.
Chavez has been a highly vocal critic of the US-led invasion and occupation of Iraq.
Chavez, a former paratrooper who won elections six years after leading a failed coup, became in 2000 the first head of state to visit former President Saddam Hussein in Baghdad since the 1991 Gulf war.
He has also boosted ties with anti-US states such as Cuba and Libya.