"They are heading down toward a million now, and in a month or two will be below a million" barrels per day, US envoy Elliott Abrams told a news briefing, adding that the decline seen in recent days could partly be attributed to the blackouts that had crippled the country. "It's a steady decline."

The OPEC member's oil production has dwindled in the last two decades, from more than 3 million bpd at the beginning of the century to between 1.2 million and 1.4 million bpd by late 2018. Most of the crude it produces now is heavy or extra heavy.