"The valuable achievement of the 171st OPEC meeting is the result of the reasonable stances of the revered minister of petroleum and his insistence on long-tern national interests of the Islamic Republic of Iran," read the letter.
NISOC supplies over 80% of Iran's total oil output and operates the fields in southern Iran.
After months of talks and rounds of meetings, OPEC finally sealed a deal on November 30 to cut production by about 1.2 million barrels per day (bpd), or about 4.5 percent of current production, to 32.5 million bpd.