Ukrainian Foreign Minister Dmytro Kuleba has urged EU states not to pay for gas imports in roubles as demanded by Russia on Wednesday.
"If any EU country bows to Putin’s humiliating demands to pay for oil and gas in roubles, it will be like helping Ukraine with one hand and helping Russians kill Ukrainians with the other," he wrote on Twitter.
"I urge relevant countries to make a wise and responsible choice," he wrote.
The Kremlin's move seemed designed to bolster a national currency hit by weeks of sanctions due to Russia's invasion of Ukraine.
It would also however undermine the sanctions imposed on Moscow's central bank because of the Ukraine war, as the bank would need to supply the roubles for the payments.
Gas flow to continue
Russia will continue to deliver gas as promised, Putin said on Wednesday, but Russia will no longer accept payments in dollars or euros.
The move will apply to blacklisted "unfriendly" countries - meaning those that have laid sanctions on Russia since its February 24 invasion - like Britain, Canada, Japan, Switzerland, Ukraine, the United States and members of the European Union.