Russian gas giant Gazprom has sent a letter to its European natural gas customers clarifying Russia’s demand for ruble-denominated gas payments. The news agency Bloomberg, which received the letter, reported on the matter.

President of Russia Vladimir Putin insists that “hostile countries” pay their gas ruble in rubles from the beginning of May. Since then, Russia has approved an arrangement in which gas buyers will have to open an account with Gazprombank. That account could be paid in euros or dollars, but Gazprombank would exchange the currency for the ruble.

Now Gazprom says in a letter quoted by Bloomberg that payments can continue to be made in euros or dollars and the currency will be exchanged for rubles through the accounts of the Russian National Clearing House.

“The procedure guarantees the transparency of the cash flows of foreign buyers and excludes the possibility of third parties being involved in the investigation,” Gazprom says.

EU countries buying gas from Russia have not yet commented on Gazprom’s letter. Italy, for example, has refused to pay for gas in rubles and Prime Minister Mario Draghi also believes that payments made through Gazprombank are in breach of sanctions. On the other hand, Germany has stated that this is not the case. The position of the European Commission is awaited.