A model of a natural gas pipeline is placed on ruble banknotes (Reuters)

Kremlin spokesperson Dmitry Peskov said during a briefing in Moscow that Russia will not deliver gas to Europe for free.

When asked what Russia would do if Europe refused to pay for Russian gas in rubles, Peskov said that those issues would be resolved as they come.

"The delivery process is very, very complicated, it's not buying some product in a store -- you buy and pay at the checkout. These are deliveries, payments, and balance sheets, these are time-stretched processes," he said, pointing out that "Now all the modalities are being worked out between the departments, with Gazprom."

However, Peskov stressed that the difficulty of the process notwithstanding, gas will not be supplied for free to Europe.

"This can be said with absolute certainty. In our situation, it is hardly possible and hardly advisable to engage in pan-European charity," he said.

The Russian president had said on March 23 his country would stop taking payments in currencies that have been "compromised", though he did note that Russia would continue supplying gas in the volumes fixed in earlier contracts.

German Economy Minister Robert Habeck said yesterday that all G7 energy ministers agreed that they will not accept Putin's decision and will not comply with it. Habeck also claimed that Putin would not have had taken this decision had he not felt like he had his "back against the wall."

Tokyo asks Japanese firms not to pay in rubles

Japanese authorities said they will tell national companies not to pay for LNG supplies from Russia in rubles if such a request is made by Russia, Chief Cabinet Secretary Hirokazu Matsuno told a press conference in Tokyo on Tuesday.

"As of now it is unknown whether the contracts on LNG supplies from Russia made by Japanese companies are covered by the demand on payment in rubles. Nevertheless, in accordance with G7 agreements, we intend to ask Japanese companies not to accept such requirements," he said.

Japan, unlike other Western countries, has not announced its refusal of Russian energy resources or its reduction of energy imports from Russia.