European countries' dependence on Russian gas and other exports has been thrown into the spotlight since Russia sent tens of thousands of troops into Ukraine on February 24 in what it called a special operation to degrade its southern neighbour's military capabilities and root out people it called dangerous nationalists.
"Russia will continue, of course, to supply natural gas in accordance with volumes and prices... fixed in previously concluded contracts," Putin said at a televised meeting with top government ministers.
"The changes will only affect the currency of payment, which will be changed to Russian roubles," he said.
Russian gas accounts for 40 per cent of Europe's total consumption and EU gas imports from Russia have fluctuated between 200 million euros to 800 million euros ($A294 million-$A1.2 billion) a day so far this year.
The possibility a change of currency could throw that trade into disarray sent some European wholesale gas prices up to 30 per cent higher on Wednesday.
The Russian rouble briefly leapt to a three-week high past 95 against the US dollar and, despite paring some gains, stayed well below 100 after the announcement.
The currency is down about 20 per cent since February 24.
"At face value this appears to be an attempt to prop up the rouble by compelling gas buyers to buy the previously free-falling currency in order to pay," Vinicius Romano, senior analyst at consultancy Rystad Energy, said.
Putin said the government and central bank had one week to come up with a solution on how to move these operations to the Russian currency and that gas giant Gazprom would be ordered to make the corresponding changes to gas contracts.
With major banks reluctant to trade in Russian assets, some Russian gas buyers in the European Union were not immediately able to clarify how they might pay for gas going forward.
Several firms, including oil and gas majors Eni, Shell and BP, RWE and Uniper - Germany's biggest importer of Russian gas - declined to comment.
As of January 27, Gazprom's sales of natural gas to Europe and other countries were primarily settled in euros, at approximately 58 per cent.
"An understandable and transparent procedure of making payments should be created for (all foreign buyers), including acquiring Russian roubles on our domestic currency market," Putin said.
Russia drew up a list of "unfriendly" countries, which corresponds to those that imposed sanctions.
Among other things, deals with companies and individuals from those countries have to be approved by a government commission.
The list of countries and territories includes the United States and Canada, all European Union countries, the United Kingdom, Ukraine, Montenegro, Switzerland, Albania, Andorra, Iceland, Liechtenstein, Monaco, Norway, San Marino, North Macedonia, Japan, South Korea, Australia, Micronesia, New Zealand, Singapore, and Taiwan.
Some of these countries, including the United States and Norway, do not purchase Russian gas.
with reporting from EFE
