Finland has accused Russia of encouraging asylum seekers to cross their common border.
Finland will extend its border closure with Russia for four weeks until February 11th.
The Interior Ministry announced the extension on Thursday. The border was scheduled to reopen on January 15th.
The 1,340 km (832 mi) border between Finland and Russia serves as the European Union’s outer border and is part of NATO’s northeast flank.
Late last year, the government closed all eight sites on the border with Russia, accusing Moscow of encouraging asylum seekers and illegal immigrants to cross. Russia denies this claim.
“According to the information collected by the authorities, there is a risk that the phenomenon will resume and spread as previously experienced,” the Interior Ministry said in a statement.
Finland joined NATO in April after decades of military non-alignment and a pragmatic friendship with Moscow. The report alleges that Russia is allowing the migration of migrants in order to destabilize the country and in retaliation for its decision to increase defense cooperation with the United States.
When the two borders were briefly opened last month, more than 300 asylum seekers entered the country from Russia within two days, the Finnish Border Guard said at the time.
An estimated 900 asylum seekers from a wide range of countries, including Kenya, Morocco, Pakistan, Somalia, Syria and Yemen, entered Finland from Russia in early November, according to border guards.
Finland is building a 200-kilometre (124-mile) fence along part of its border, expected to be completed by 2026.