Saudi Arabia and other Opec+ oil producers on Sunday announced voluntary cuts to their production amounting to around 1.15 million barrels per day in a surprise move they said was aimed at supporting market stability.

The group had been largely expected to stick to its already agreed 2 million bpd cuts when its ministerial panel, which includes Saudi Arabia and Russia, meets virtually on Monday.

The unexpected 1.15 million barrel per day production cut could lift global oil prices by $10 per barrel, the head of investment firm Pickering Energy Partners said on Sunday.

The output reduction “will firm prices meaningfully,” said Dan Pickering, co-founder of the Houston-based firm.

Last October, Opec+, which comprises the Organization of Petroleum Exporting Countries (Opec) and allies led by Russia, agreed output cuts of 2 million bpd from November until the end of the year, angering Washington.

The US has argued that the world needs lower prices to support economic growth and prevent Russian President Vladimir Putin from earning more revenue to fund the war in Ukraine.

Sunday’s unexpected voluntary cuts, which start from May, come in addition to the ones already agreed in October by the cartel.

Riyadh said it would cut output by 500,000 bpd while Iraq will reduce its production by 211,000 bpd, according to official statements.

The UAE said it would cut production by 144,000 bpd, Kuwait announced a cut of 128,000 bpd while Oman announced a cut of 40,000 bpd and Algeria said it would cut its output by 48,000 bpd. Kazakhstan will also cut output by 78,000 bpd.

Russia’s deputy prime minister Alexander Novak also said on Sunday that Moscow would extend a voluntary cut of 500,000 bpd until the end of 2023.

Moscow announced those cuts unilaterally in February following the introduction of Western price caps.

After Russia’s unilateral reductions, US officials said its alliance with other Opec members was weakening, but Sunday’s move shows the co-operation is still strong.

The Saudi energy ministry said in a statement that the kingdom’s voluntary cut was a precautionary measure.

Oil prices fell to 15-month lows earlier this month in response to the banking crisis that followed the collapse of two US lenders and resulted in Credit Suisse being rescued by Switzerland’s biggest bank UBS.