Map shows how Russia's border with NATO more than doubles with Finland as a member

• Finland officially became a member of the NATO military alliance on Tuesday.

• Finland has an 830-mile border with Russia, meaning Russia's border with NATO more than doubles.

Finland became the latest member of NATO on Tuesday, infuriating Russian President Vladimir Putin who has long aimed at rolling back the military alliance's borders.

Finland, along with its neighbor Sweden, applied to join NATO in May 2022, reversing decades-long policies of maintaining military neutrality on the global stage.

Russia's ongoing, unprovoked war in Ukraine prompted the nations to change their position.

Finland's presence in the alliance more than doubles the border between NATO countries and Russia.

Before Tuesday, NATO had land borders with Russia that spanned 754 miles across northern Norway, eastern Latvia and Estonia, and the borders with Poland and Lithuania around Russia's Kaliningrad region.

Finland joining adds 830 miles of continuous border along northwestern Russia, taking the total to 1,584 miles.

The increase in public and political support in Finland for joining NATO came after Russia's invasion of Ukraine in February 2022.

Experts have said the development is a noted failure for Russia, which partly justified its invasion of Ukraine as a way to stop NATO expanding further.

Russian officials prior to Finland and Sweden's official application repeatedly threatened the two countries, saying they would have to retaliate against a membership bid.

Russia said in response to Finland's official membership that it will boost its military presence near their joint border.

"We will strengthen our military potential in the western and northwestern direction," Russia's Deputy Foreign Minister Alexander Grushko told Russian outlet RIA on Monday, according to Reuters.

He added: "In the event that the forces and resources of other NATO members are deployed in Finland, we will take additional steps to reliably ensure Russia's military security."