Saudi Arabia and some OPEC members clashed over who would produce how much oil ahead of a contentious group meeting on Sunday, people familiar with the matter said, in a sign of growing tensions within the cartel amid concerns over weakening global energy demand.

Saudi Arabia, the de facto leader of the Organization of the Petroleum Exporting Countries, demanded smaller African producers cut their quotas, according to the people. At the same time, the kingdom was in talks with the United Arab Emirates, another powerful member of the group, to allow it to produce more, they added.

Saudi Oil Minister Prince Abdulaziz bin Salman called some of the African delegates to his hotel suite in Vienna on Saturday and told them that their production quotas within the group would be reduced, the people said. They walked out of the meeting without a deal, the people added. African countries such as Nigeria and Angola have often struggled to even meet their current production targets for various reasons, including pandemic shutdowns that proved hard to reverse and years of underinvestment.

Representatives for the energy ministries of Saudi Arabia, the U.A.E., Nigeria, Angola, Equatorial Guinea, Gabon and the Republic of Congo didn’t immediately respond to requests for comment.

A production cut of up to 1 million barrels a day is on the table as OPEC and its Russia-led allies, known as OPEC+, meet this weekend in Vienna to decide on a production plan, delegates said. The broader 23-member group accounts for more than half the world’s oil production. The delegates said a cut in production is expected to prop up crude prices amid concerns that a slowing global economy would crimp energy demand. Still, most members don’t want to give up their allotted production quotas as that affects their overall revenues.

If approved, Sunday’s output cut would be the third by members of OPEC+ since October, when they slashed output by 2 million barrels a day. In April, some of the group’s largest members, including Saudi Arabia and Russia, cut a further 1.6 million barrels a day. The decision to cut had drawn rebuke from the U.S., which at the time had requested Saudi Arabia and OPEC to increase production to help tame inflation. It led to U.S. accusations that Riyadh was siding with Moscow in Russia’s invasion of Ukraine.

Brent crude, the international oil benchmark, is down more than 20% since OPEC and its allies first jolted the market with output cuts in October. Another output cut on Sunday isn’t expected to evoke any major reaction from Washington as most analysts expect that oil prices will continue to trend low.