The European Union has banned imports of Russian diesel.

Despite Russia being the European bloc's largest supplier of the fuel, prices actually fell 1.6 percent on Monday amid lower demand and months of stockpiling.

“The expectation was that, when the ban came in, diesel supply into Europe would tighten but, actually, that’s currently not materializing,” Mark Williams, a research director at consultancy Wood Mackenzie, told CNN.

In the months leading up to the ban, companies, and countries prepared by importing more Russian diesel - with imports up nearly 19 percent in the fourth quarter of 2022 compared to the year before.

At the same time, warmer-than-expected temperatures have decreased the use of diesel fuel over the winter.

With Russian diesel having accounted for a quarter of European imports, countries in the EU have turned to United States, the Middle East, and parts of Asia to try to meet the shortfall.

It is not clear if such efforts will be able to completely offset Russia's supplies, and it will take months for the true impact to be felt as stockpiles are used up.

Data center companies including Equinix and Digital Realty last year said that they responded to Russia's invasion of Ukraine and the subsequent European energy crisis by stockpiling backup power reserves.