"I am happy to announce that a historic agreement has been reached", said Qatar's Energy Minister Mohammed Bin Saleh Al-Sada, whose country holds the rotating presidency of the Organisation of the Petroleum Exporting Countries (OPEC).
The decision, taken at a meeting at OPEC headquarters in Vienna, follows the cartel's announcement on November 30 it would reduce its output by 1.2 million barrels per day (bpd) from January, to 32.5 million bpd.
Russia had already signalled it would provide half of that production cut in the first half of 2017.