(Reuters) – Gazprom (MCX) said Tuesday that it was implementing President Putin’s decree on enforcing gas supply payments in roubles. When asked for clarification about European Commission guidance regarding Russia’s plan, the Kremlin did not provide any further information.

According to the European Commission, European companies must meet additional requirements. This includes a declaration that they consider their contractual obligations complete after they have denominated non-Russian currency.

Dmitry Peskov (Kremlin spokesperson) stated that “all the contacts with gas buyers have been made through Gazprom”, and Gazprom would publish information about the outcomes of the talks.

Gazprom did not respond to our request for comment.

According to a source who was not authorized to speak on behalf of the buyers, there is no way for the buyer’s representatives to know how the plan will be implemented. However, work continues.

Russian President Vladimir Putin requested that all countries considered “unfriendly” agree to implement the program that allows them to open Gazprombank account and then make payments in Euros or Dollars that are converted into Russian rubles.

Peskov stated that payments to Putin for delivery orders made after his decree went into effect are expected in May.

Russia had announced this plan following the launch of what Moscow called a special military operations in Ukraine, Feb. 24, prompting Western sanctions including the freezing a portion of Russia’s forex and gold reserves.

The rouble payment plan was rejected by most European gas buyers.

Moscow warned Europe that it could cut its gas supply if it didn’t pay in roubles. Since then, several Russian gas buyers said they may be willing to meet Moscow’s demands.

Uniper is Germany’s biggest Russian gas importer. It said Monday that future supply could be paid for without breaking any European Union sanctions.

Hungary stated that it had planned to purchase Russian gas in euro through Gazprombank. The bank will convert the payment to roubles to fulfill the new requirement.