Moscow threatens to react to the statement of the official Helsinki about its intention to join NATO.

Key Finnish politicians have been warned that Russia may stop gas supplies to Finland on Friday, Iltalehti newspaper reported on Thursday, citing unnamed sources.

The newspaper did not specify where the warning came from, and Reuters could not verify the information.

Finnish President Sauli Niinisto and Prime Minister Sanna Marin said on Thursday that Finland would “without delay” apply for NATO membership, to which Russia promised retaliatory actions.

Most of the gas used in Finland is supplied from Russia, but gas accounts for only about 5% of the country’s annual energy consumption.

However, the loss of most of the gas supplies means that industrial giants such as Neste and Metsa, as well as other companies in the forestry, chemical and food industries will have to find alternative energy sources or adapt their production.

On May 5, the Finnish government announced that it was ready for Russia to stop gas supplies at the end of May in response to Finland’s refusal to comply with the Russian demand to pay for gas in rubles.

Having a direct pipeline connection with Russia, Finland and the Baltic states depend on Russian gas more than other European countries. If Russian gas supplies are cut or curtailed, Finland, Estonia, Latvia and Lithuania may have to reduce demand, the European network of gas operators ENTSOG said in its summer forecast in April.