Russia's Gazprom has halted gas exports to neighbouring Finland, confirming what Finnish system operator Gasgrid Finland said earlier.

After Russia invaded Ukraine on February 24, Moscow has asked clients from "unfriendly countries" — including EU member states — to pay for gas in roubles, a way to sidestep Western financial sanctions.

Gazprom said in a statement it had "completely stopped gas deliveries" as it had not received rouble payments from Finland's state-owned energy company, Gasum, "by the end of the working day on May 20".

"Starting April 1, payments for gas need to be made in roubles using new bank details, about which the counterparts were informed in a timely manner," Gazprom said.

Gazprom said it had supplied 1.49 billion cubic metres of natural gas to Finland in 2021, equal to about two-thirds of the country's gas consumption.

But natural gas accounts for around eight per cent of Finland's energy.

Finland said it would make up for the shortfall from other sources through the Baltic connector pipeline, which connects Finland to Estonia, and assured filling stations would run normally.

Saturday's halt to gas shipments follows Moscow cutting off Poland and Bulgaria last month in a move the European Union described as "blackmail".