OPEC just pumped its lowest amount of crude in more than 20 years — and it wasn't by choice.

Output from the 11-member group fell by 1.06 million barrels per day (bpd) in May to 16.13 million bpd, according to a Reuters survey published Thursday. That's the lowest monthly figure since at least 2000. To put it in perspective: it's even lower than during the COVID-19 pandemic in 2020, when global demand crashed.

The reason? A U.S. naval blockade that started on April 13 has slashed Iran's exports to their lowest in at least six years. And Iran's effective closure of the Strait of Hormuz — a narrow waterway that about 20% of the world's oil passes through — has choked shipments from other Gulf producers too.

Iran took the biggest hit. Its crude and condensate exports fell sharply as the blockade stopped tankers from leaving. Saudi Arabia also saw a further decline, though Iraq managed to increase supply by burning more oil at home for power generation.

Venezuela and Nigeria pumped a bit more, but it wasn't nearly enough to offset the losses.

The survey, which uses flow data from financial group LSEG, tracking firms like Kpler, and sources inside oil companies, OPEC, and consultancies, excludes the United Arab Emirates. The UAE quit OPEC on May 1, so its numbers weren't counted.

Here's the twist: eight members of the wider OPEC+ group — which includes allies like Russia — had actually agreed to raise production in May. But the Iran war and the U.S. blockade made that impossible.

"The Iran war and U.S. blockade made that impossible," the survey sources said.

What happens next? With the Strait of Hormuz effectively blocked and the U.S. blockade still in place, global oil supplies are tightening. That usually means higher prices at the pump — and more pressure on economies already dealing with inflation.

For Nigeria, the small production increase is a rare bright spot, but it's a drop in the ocean. The country has struggled for years to meet its OPEC quota due to theft, underinvestment, and aging infrastructure. Pumping more now won't change the fact that the cartel's overall output is at a historic low.

  • OPEC May output: 16.13 million bpd (lowest since 2000)
  • Month-on-month drop: 1.06 million bpd
  • U.S. blockade on Iran started April 13
  • Iran exports at lowest in 6+ years
  • UAE quit OPEC effective May 1
  • 8 OPEC+ members agreed to raise output in May but couldn't due to blockade and Hormuz closure