Finland is ready to stop gas supplies from Russia, Reuters reported, citing the Minister for European Affairs of Finland Tytti Tuppurainen.

Finland's government said on 28 April that it would not accept Russia's demand to pay for gas in rubles, which could lead to a halt in gas supplies, as has happened with Poland and Bulgaria.

Finland's state-owned gas operator Gasum is due to respond this month to a letter on the rouble payments from Russia's Gazprom. A source familiar with the matter told Reuters the deadline for its response is May 20.

The country must also announce as early as next week whether it will join NATO, which Russia opposes.

"Finland is prepared for the possibility that gas deliveries from Russia would end," Finland's Minister of European Affairs Tytti Tuppurainen told Reuters.

He said Finland has taken measures, including the use of alternative energy sources, and the government also recently announced that it would lease a floating LNG terminal from Estonia.

Roughly 60-70% of the gas used in Finland originates from Russia. However, it accounted for little more than 5% of the country's total energy consumption last year, Statistics Finland's preliminary data showed, with oil, wood-based biomass and nuclear power being the main sources of energy.

Most natural gas is used in industrial production, gas markets expert Heikki Lindfors of Finnish Energy interest group said.

"The share of gas in Finland's total consumption is small in percentages, but it is used by industrial sectors in which it cannot be easily replaced," he said, adding some companies could end up having to stop their production.

The largest user is Finland's chemical industry, which includes energy group Neste's oil refining activities in Porvoo.