Western economies agreed on new price caps on Friday on Russia's exports of oil products that U.S. Treasury Secretary Janet Yellen said would build on the crude oil cap set in December and further limit Russian oil revenues while keeping global energy markets supplied.

The coalition imposing the measures, the Group of Seven economies, the EU and Australia, set the new price caps at $100 per barrel on products that trade at a premium to crude, principally diesel, and $45 per barrel for products that trade at a discount, such as fuel oil and naphtha.

The price caps, together with a European Union ban on Russian oil product imports that also comes into force on Sunday, seek to limit Moscow's ability to fund its war in Ukraine, which began nearly a year ago.