Saudi energy minister Prince Abdulaziz bin Salman flanked by Venezuelan oil minister Manuel Quevedo, left, and Russian energy minister Alexander Novak at Opec's annual meeting in Vienna in December. REUTERS
Saudi energy minister Prince Abdulaziz bin Salman flanked by Venezuelan oil minister Manuel Quevedo, left, and Russian energy minister Alexander Novak at Opec's annual meeting in Vienna in December. RShow more

Opec+ has some 'work to do' to address compliance, Saudi Arabia's energy minister says