Investing.com -- Russian oil production has decreased since the start of 2026, Deputy Prime Minister Alexander Novak said Thursday, attributing the drop to unplanned maintenance at refineries.

This marks the first acknowledgment by a Russian official that output has declined this year. Russia, the world's third-largest oil producer, stopped publishing oil production data in April 2023, just over a year after its war with Ukraine began.

Novak did not explain the reason for the refinery maintenance, though Ukraine has increased attacks on Russian refineries in recent months.

"Current production is indeed somewhat lower than it was at the beginning of the year," Novak told reporters at the St Petersburg International Economic Forum. "This is due to the fact that a number of our oil refineries are currently undergoing unscheduled maintenance."

He added that Russia is using its export infrastructure to maximum capacity. Novak said production will increase and return to previous levels as refineries resume full operations.

The International Energy Agency reported that Russia's crude oil production fell by 460,000 barrels per day in April from a year earlier to around 8.8 million barrels per day.

Novak also said the OPEC+ group of oil-producing countries remains important in the global oil market despite the United Arab Emirates leaving the alliance.

"In any case, OPEC and our agreements, which have proven their effectiveness, help smooth fluctuations and volatility in global markets," he said.