Iranian oil technician Majid Afshari makes his way to the oil separator facilities in Iran's Azadegan oil field southwest of Tehran, Iran.
The Sunday report by the semiofficial Mehr news agency quotes Mahmoud Bahmani as saying Iran will "confront" hostile policies.
The remark is the first reaction by a senior Tehran official on the day that an EU embargo on Iranian oil goes into effect.
The EU measures are intended to pressure Iran over fears that it is developing nuclear weapons. Iran denies the charges.
Iran is the second largest producer in OPEC and earns some 80 percent of its foreign revenue from exporting crude. Other U.S. and EU sanctions have already hit Iran's economy hard.