Saudi Arabia opened the taps in May, increasing its oil output ahead of a critical meeting of crude-producing nations that will determine whether it's time to unwind a deal to limit production.
The Saudis reported the supply spike following reports that the Trump administration sought assurances that Riyadh would raise output to offset the impact of Washington restoring sanctions on Iran, Saudi Arabia's chief regional rival and OPEC's third biggest producer.
OPEC's top producer said it hiked output by 161,000 barrels a day in May. That brought the Saudis' monthly production to just over 10 million barrels a day, pushing it towards the ceiling it agreed to in November, 2017.
The oil cartel's overall output was relatively steady, rising by about 34,000 barrels a day to nearly 31.9 million barrels a day, according to independent sources cited in OPEC's monthly report. That total reflects a Saudi output figure slightly lower than the kingdom reported itself, and a monthly jump that was roughly half as large.
To be sure, the increase is not proof that Saudi Arabia is getting ahead of OPEC policy before the wider group meets on June 22 in Vienna. The Saudis have also pumped well below their quota throughout the production-cutting agreement, which has been in place since January 2017. They also warned fellow OPEC members that their output exceeded 10 million barrels a day in May, Reuters reported this week.