NATO members formally sign the accession agreements of Finland and Sweden on Tuesday as the two nations move one step closer to becoming full members of the military alliance.

The measure will aggravate Russia's geopolitical isolation following its invasion of bordering Ukraine in February and subsequent armed conflicts in the eastern European country.

Their impending NATO memberships have drawn considerable attention since they represent a significant modification in both their security strategies and Europe's broader defense system. For the majority of recent history, both nations had maintained a neutral attitude toward Russia, but the aggressive invasion of Ukraine compelled them to change course, as per a report published by NPR.

After the signing of the protocols, NATO Secretary-General Jens Stoltenberg said Finland and Sweden "will make strong and important contributions" to the military alliance."

"Our forces are interoperable. They have trained, exercised, and served together for many years," Stoltenberg noted, according to a CNBC report.

Both countries submitted membership applications to the alliance in May, and according to Stoltenberg, this has been the "fastest accession procedure in NATO's history thus far."

The 30 ambassadors and permanent representatives will formally ratify the choices made at the NATO summit last week, when the alliance decided to extend invitations to Sweden and Finland, two neighbors of Russia, to join the military club.

Erdogan's Warning

Despite the alliance's agreement, Turkey's legislative approval could yet create challenges for their actual admission as members.

Tuesday's expected signing-off brings both nations deeper into NATO's fold. As close partners, they already attended some meetings that involved issues that immediately affected them. As official invitees, they can attend all meetings of the ambassadors even if they do not yet have any voting rights.

Despite the agreement in the military alliance at a summit last week in Madrid, parliamentary approval in member state Turkey could still pose problems for the Nordic duo's final inclusion as members.

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President Recep Tayyip Erdogan of Turkey warned that if the two nations do not grant its demand to extradite "terrorism" suspects connected with banned Kurdish organizations or the network of an exiled religious figure accused of planning a failed coup in Turkey in 2016, Ankara may still block the membership process.

Turkey also expects Sweden and Finland to lift the prohibition on selling weapons to Anakara.

The ambassadors and permanent representatives of the two nations have already participated in meetings on matters that directly touch them as partners. Even though they do not yet have voting privileges, they are permitted to attend all meetings of the ambassadors as official invitees.

Putin Blasts NATO's 'Ambitions'

Russian President Vladimir Putin accused NATO last week of seeking to assert its "supremacy" through the Ukraine war and blasted the "imperial ambitions" of the military alliance, per a report from Al Jazeera.

Putin stated: "With Sweden and Finland, we don't have the problems that we have with Ukraine. If they want to join NATO, go ahead. But they must understand there was no threat before, while now if military contingents and infrastructure are deployed there, we will have to respond in kind and create the same threats for the territories from which threats towards us are created."

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