He was a veteran negotiator and shepherded Iran's oil policy in OPEC.

Iranian Minister of Petroleum Bijan Zangeneh immediately expressed his deepest feelings about Mr. Kazempour's demise. 

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.

"I can't believe that my compassionate friend, Hossein Kazempour Ardebili, has suddenly left this mortal world for eternal destiny and I be sitting in his grief. But death is both a reality and a truth from which sooner or later there is no escape and we can do nothing but surrender,” said Zangeneh in a message of condolence.

“Nearly 23 years of close cooperation with Hossein Kazempour puts me in a position where I can testify that he was a pious, cultivated, humble, very honorable man and a true and unwavering servant of the Iranian nation, loyal to the Islamic Republic and a lover of Iran for whom pride and progress of Iran was a constant concern.”

“He was a prominent diplomat who defended our national interests intelligently and vigorously in OPEC for more than three decades, in the most difficult circumstances and in spite of all adversity,” said Mr. Zangeneh.

Also, in a message, the Minister of Foreign Affairs Mohammad Javad Zarif expressed his condolences on the death of Hossein Kazempour Ardebili.

The message reads: "The death of our dear brother, modest friend and honorable colleague, Hossein Kazempour Ardebili, a veteran and unique diplomat of our country, is a great loss for the diplomatic community.

“This survivor of the June 28, 1981 bombing, he had always remained an astute and dignified defender of the national interests of the country either as an ambassador or minister or deputy minister and served as a reliable, exact and straightforward advisor to the Islamic Republic of Iran’s officials.”