A vital figure in Iran's international oil policy and staunch Zangeneh aide, he was hospitalized in Tehran on Friday.

Kazempour Ardebili was key in forming Iran’s position in the global oil arena, especially at the Organization of the Petroleum Exporting Countries (OPEC).

He served as the country's deputy foreign minister and deputy minister of petroleum in the 1980s.

Kazempour was also Tehran’s ambassador to Japan in the early 1990s, while at the same time serving as OPEC governor.