U.S. President Donald Trump was among those wondering how much more oil OPEC would deliver. In reality, ministers said several countries are unable to pump more so the real output boost would have been smaller - ranging from Iran's 500,000 barrel-a-day estimate up to Iraq's prediction for as much as 800,000.
OPEC's official statement said members agreed to return to 100 percent compliance with the 2016 deal beginning on July 1.
The organisation, which agreed to restrict output by 1.2 million bpd, has consistently over-complied, largely thanks to involuntary declines in the likes of Venezuela and Angola, but also to Saudi Arabia, which has cut crude output by more than it had pledged to in order to make up for any members that failed to meet their targets.
Two OPEC sources said the group agreed that OPEC and its allies led by Russian Federation should increase production by about 1 million barrels per day (bpd), or 1 percent of global supply.
Saudi Energy Minister Khalid al-Falih said OPEC and non-OPEC combined would pump roughly an extra 1 million barrels per day (bpd) in coming months, equal to 1 percent of global supply. A meeting with the primary goal to discuss OPEC's "Exit Strategy" after two steady years of crude oil price increases from the depths of $27 (from January 2016) to an average of over $70 through 2018 thus far. Compliance has been well above 100% this year since some countries, notably Venezuela, have seen a drop in production.
Oil hit almost $80 per barrel last month, sending gasoline prices in the United States above $3 per gallon in many areas for the first time in years. On that same note, USA oil stockpiles - whilst lingering near their five-year average from 2013 to 2018 - remain approximately 29 percent above their 2008-2013 five-year averages.
Another big uncertainty for oil is the escalating dispute between the United States and its trading partners, which could hit USA crude oil exports to China.
Overall, Crude oil prices may show weakness through the second half of 2018, with the prospect of OPEC production growth mostly influencing market psyche into a "Bearish" mode.
The most recent price rally followed an Opec decision to restrict supply in an effort to drain global inventories.
"Yields.(are) still lower from a couple of weeks ago and that's because of the uncertainty on the US trade situation with China", said Lou Brien, market strategist at DRW Trading in Chicago. USA light crude was $1.80 higher at $67.34.
Oil prices have been on a roller-coaster ride over the last few years, with the worldwide marker, Brent, trading above $100 a barrel for several years until 2014, dropping to nearly $26 in 2016 and then recovering to over $80 last month.