New Nato entrants must be approved by all existing members of the Western military alliance, and support for Finland's application remains pending from Turkey and Hungary.

Spooked by Moscow's invasion of Ukraine, Finland and Sweden dropped their decades-long policies of military non-alignment and applied to join the North Atlantic Treaty Organization in May last year.

The Scandianavian nations' bids to join the 30-member alliance, which is arming Kyiv against President Vladimir Putin's army, have been ratified by all but Hungary and Turkey.

Erdogan's comments during a televised meeting with younger voters came days after Ankara suspended Nato accession talks with the two countries.

Finland has a history of wars with Russia, but the forest-covered border is still only marked with signs and plastic lines for most of its 1,300km length.

The government says the move will lead to a significant drop in cross-border traffic after almost 17,000 Russians crossed the border into Finland.

Some Finns have voiced support for Sanna Marin and others have raised questions about her judgement.

Ties between the US and Turkey remain sour as the two Nato allies are at odds over a host of issues including Syria policy and Ankara's purchase of Russian defense systems.

Any Nato membership deal must be unanimously approved by the 30 members of the alliance, and fears are now mounting that Turkey could delay the Nordic countries' bids indefinitely.

Sweden and Finland were both neutral throughout the Cold War, and their decision to join Nato is one of the most significant changes in Europe's security architecture for decades.

Less than three months after Russia invaded Ukraine on Feb 24, the move is a stunning reversal of Finland's policy on military non-alignment dating back more than 75 years.

The Kremlin responded by saying that Putin viewed any end to Finland's military neutrality as a 'mistake'.