Finland must apply to join Nato without delay in the wake of Russia’s attack on Ukraine, its president and prime minister have said, confirming a historic change in the Nordic country’s security policy after decades of military non-alignment. Sauli Niinistö and Sanna Marin made the call in a joint statement, adding: “We hope that the national steps still needed to make this decision will be taken rapidly within the next few days.” Nato membership would strengthen Finland’s security, the two leaders said, and as a member of Nato: “Finland would strengthen the entire defence alliance. Finland must apply for Nato membership as a matter of urgency.” Finland shares an 810-mile (1,300km) border with Russia and has long viewed joining the US-led alliance as an unnecessary provocation of Moscow, but Vladimir Putin’s invasion of Ukraine on 24 February has led to a profound shift in its thinking. 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. The president, prime minister and senior cabinet ministers will meet on Sunday to make the formal decision on submitting the country’s membership application. A positive decision would then be presented to parliament for approval early next week. Neighbouring Sweden is thought likely to follow suit, with its ruling Social Democrats due to decide on Sunday whether to overturn their longstanding opposition to Nato membership, paving the way for an application to join the 30-nation alliance. Sweden’s foreign minister, Ann Linde, said Niinistö and Marin’s statement was “an important message”, adding that Finland was “Sweden’s closest security and defence partner” and its assessments “must be taken into account”. Sweden’s Expressen daily, citing unnamed sources, said Stockholm’s decision would be made on Monday, with a formal application for membership to be submitted immediately afterwards. Nordic media have previously said the two countries were likely to submit a joint application. Nato’s secretary general, Jens Stoltenberg, said last month Finland and Sweden would be welcomed “with open arms” and it should be possible to allow the two to join “quite quickly”, although the process of formal ratification by all the alliance’s members could take several months. Russia has repeatedly warned Finland and Sweden against joining Nato, saying the “serious military and political consequences” of such a move would oblige it to “restore military balance” by strengthening its defences in the Baltic Sea region, including by deploying nuclear weapons. Dmitry Medvedev, the former Russian president and long-time ally of Vladimir Putin, said on Thursday that western countries’ “proxy war with Russia” would “increase the likelihood of a direct and open conflict between Nato and Russia”. Urging the west not to “lie to yourself and others” and “choke in the paroxysms of Russophobia”, Medvedev said such a conflict “always has the risk of turning into a full-fledged nuclear war” and that this would be “catastrophic for everyone”. Other governments in the region welcomed Helsinki’s statement. Denmark’s prime minister, Mette Frederiksen, said Finnish membership would “strengthen Nato and our common security”. Copenhagen would do everything for a quick admission process, she said. Estonia’s prime minister, Kaja Kallas, said her country supported Finland’s rapid accession. “History being made by our northern neighbours,” she tweeted. “You can count on our full support. We support a rapid accession process. From our side will make necessary steps quickly.” Finland’s foreign minister, Pekka Haavisto, told the European parliament on Thursday that accession to Nato would strengthen security in the region. Norway, Denmark and the three Baltic states are already Nato members and the addition of Finland would “bring added value”, he said. READ ALSO: Buhari Asks CBN Gov, Godwin Emefiele, Ambassadors, Heads Of MDAs, Others With Political Ambitions To Hand Over Finland and Sweden are officially non-aligned but became Nato partners – taking part in exercises and exchanging intelligence – after abandoning their strict neutrality when they joined the EU in 1995 after the end of the cold war. 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. Marin and her Swedish counterpart, Magdalena Andersson, said at a joint press conference last month that Russia’s invasion of Ukraine had changed Europe’s whole security landscape and “dramatically shaped mindsets” in the Nordic countries. Nato’s common security guarantee rests on article 5, the alliance’s cornerstone, which says an attack on one Nato member is an attack on all. It has only been invoked once in the organisation’s history, in response to the September 11 2001 terrorist attacks.