Russia is halting its supply of natural gas to Finland.
The Finnish state-owned energy firm Gasum said it was “regrettable” but there would be no disruption to customers.
It comes after Finland said it would not pay for supplies in roubles amid an announcement from the country that it was applying for Nato membership.
Despite the ongoing invasion of Ukraine, Russia is still supplying gas to many European countries.
But after Western allies imposed heavy sanctions on Russia, the Kremlin retaliated by saying “unfriendly” countries must pay in roubles.
The EU has blasted the move as “blackmail”.
Much of Europe is heavily reliant on Russian energy, with plans to try and wean themselves off it.
Gasum’s chief executive Mika Wiljanen said: “It is highly regrettable that natural gas supplies under our supply contract will now be halted.
“However, we have been carefully preparing for this situation and provided that there will be no disruptions in the gas transmission network, we will be able to supply all our customers with gas in the coming months,” he added.
A Kremlin spokesman said “it is obvious that nobody is going to deliver anything for free”.
On Sunday, Russia cut electricity supplies to Finland amid threats to retaliate should it apply to join Nato.
The move was announced by NAO Nordic, a subsidiary of Russian state energy holding Inter RAO that sells its electricity on the Nordic market.
“We are forced to suspend the electricity import starting from May 14,” it said, citing a failure to receive payment for electricity sold in May.
“This situation is exceptional and happened for the first time in over 20 years of our trading history,” RAO Nordic added.
Finland’s electricity network operator said it would cope without the Russian power supply.
It comes after Finland took the landmark decision to apply to join Nato.
Finnish President Sauli Niinisto and Prime Minister Sanna Marin said in a joint statement that their country should submit an application to join the military alliance.
Responding to the move, the Kremlin said Finland joining Nato would be a “threat” to Russia and would not further stability in Europe.
UK Prime Minister Boris Johnson said the move was a “historic day for our alliance and the world” while US President Joe Biden said Finland and Sweden met the requirements to join Nato.