Veteran oil minister, Bijan Namdar Zanganeh, will retire when President Hassan Rouhani’s term ends this year, closing a career that started with the birth of the Islamic Republic in 1979 and has often been defined by his country’s turbulent relationship with the U.S. OPEC’s longest-serving oil minister said he won’t accept any proposal from Rouhani’s successor — who’ll be chosen during next month’s election — to continue in his post.