Kremlin threatens retaliation after Finland leaders say it must join Nato

The Finnish daily Iltalehti reported that key Finnish politicians had been told Russia could halt gas supplies to Finland on Friday, although it did not say where the warning came from or whether it was in response to the Nato announcement.

Finland shares an 810-mile (1,300km) border with Russia and has for decades maintained a strict policy of military non-alignment, viewing membership of the US-led alliance as an unnecessary provocation of Moscow.

Public support for Nato membership has trebled in Finland, with the latest poll by the public broadcaster Yle showing 76% of Finns in favour compared with about 25% before the invasion, with only 12% against.

Finland declared independence in 1917 after more than a century of Russian rule, and its heavily outnumbered army twice fought off Soviet forces during the second world war before ceding some border territory. Sweden has not fought a war for 200 years.