Saudi Arabia's Oil Minister Khalid al-Falih talks to journalists at the beginning of an OPEC meeting in Vienna, Austria December 6, 2018.

Saudi Arabia's Oil Minister Khalid al-Falih arrives at the OPEC headquarters in Vienna, Austria December 6, 2018.

UAE's Oil Minister OPEC President Suhail Mohamed Al Mazrouei and OPEC Secretary General Mohammad Barkindo wait for the beginning of an OPEC meeting in Vienna, Austria December 6, 2018.

Iraq's Oil Minister Thamir Abbas Al Ghadhban talks to journalists at the beginning of an OPEC meeting in Vienna, Austria December 6, 2018.

The logo of the Organisation of the Petroleum Exporting Countries (OPEC) is seen at OPEC's headquarters in Vienna, Austria December 5, 2018. REUTERS/Leonhard Foeger

Iran's Oil Minister Bijan Zanganeh talks to journalists at the beginning of an OPEC meeting in Vienna, Austria December 6, 2018.

Oman's Oil Minister Mohammed bin Hamad al-Rumhy talks to journalists as he leaves the OPEC headquarters in Vienna, Austria December 5, 2018.

Saudi Arabia's Oil Minister Khalid al-Falih arrives at the OPEC headquarters in Vienna, Austria December 6, 2018.