Russia’s oil-export revenue contracted to $17.7 billion in August, the lowest since at least March, as a decline in crude prices more than offset higher supplies abroad, according to the International Energy Agency.

That’s a drop of $1.2 billion from a month earlier, even as Russia’s daily crude and oil products exports rose by 220,000 barrels to 7.6 million barrels, the IEA estimated. 

“Russian oil revenues may take a further hit when EU sanctions on Russian oil imports go into effect starting from December,” the IEA said in its monthly report on Wednesday.

The European Union is set to halt most crude purchases from Russia from Dec. 5, aiming to reduce the flow of petrodollars to the Kremlin after its invasion of Ukraine. From Feb. 5, an EU ban on Russian oil-product shipments takes effect. Another blow to Russia’s oil-export revenues could come from the price cap that Group of Seven nations plan to set.

While Russian officials, including President Vladimir Putin, pledged to halt exports to countries that introduce such a measure and re-direct flows to those nations that continue to work on market terms, the price cap could further increase the discount for remaining buyers of Russian fuel.

In August, the average price for benchmark Urals crude fell 4.7% from a month earlier to $74.73 a barrel, according to Russia’s Finance Ministry. 

Russia’s federal budget, which gets over a third of its revenue from oil and gas, received 671.9 billion rubles ($11.1 billion) in August, the lowest inflow of petrodollars in 14 months, according to Bloomberg calculations based on Finance Ministry data.