Russia's ban on oil supplies to countries and companies that comply with a price cap imposed by the West came into effect on Wednesday.
The decree, signed by President Vladimir Putin on Dec. 27, prohibits the supply of Russian crude oil and oil products "at all stages" if contracts directly or indirectly abide by the price cap.
In early December, the G7, EU and Australia agreed to a $60 per barrel price cap on Russian seaborne crude oil, in response to Moscow's war on Ukraine.
The ban will remain in place for five months, with exceptions based on special authorization by the president.
Exporting companies have to provide monthly information to the customs authority on concluded contracts and prices, as well as data on monitoring the non-use of the price cap by the final buyer.
If the customs authorities discover the use of the price cap, the transportation of energy resources will be suspended.