Finland is closing all but one of its land border crossings with Russia, escalating a standoff between the two countries over an influx of migrants that Finnish officials blame on Moscow.
Starting on Friday, only the Raja-Jooseppi crossing in northern Lapland will stay open to travelers, while all seven other land crossings will be closed. Last week, Finland closed four of the entry points.
“Unfortunately, that did not manage to stop this phenomenon,” the Finnish prime minister, Petteri Orpo, said at a news conference on Wednesday night, adding that the situation at the border was deteriorating amid signs that the Russian authorities were helping asylum seekers make their way to the country.
“We do not accept such activity,” he said, adding that Finland would take further measures if necessary.
Mr. Orpo was scheduled to make a statement about border policy in the Finnish Parliament on Thursday.
The border dispute is the latest sign of erosion in the relationship between Finland and Russia, countries that share an 830-mile border. Their ties have deteriorated since Russia’s full-scale invasion of Ukraine last year.
Concerned that Finland could one day become a target of Russian aggression, the country sought and, in April, obtained membership in the North Atlantic Treaty Organization, becoming the 31st member of the military alliance and in the process angering Moscow.
Since then, Finland has accused Russia of encouraging and helping asylum seekers — mainly from the Middle East and Africa, according to the Finnish border authorities — to reach the border with Finland even though they did not have the proper documents. About 700 have arrived in November, a sharp increase from previous months, the Finnish authorities said.
Maria V. Zakharova, spokeswoman for Russia’s Foreign Ministry, has called the allegations “unsubstantiated” and dismissed them as “misinformation.” On Wednesday, she wrote on Telegram that Russia was open to dialogue on the issue.
On Wednesday, the authorities in Finland doubled down on their accusations. “Russia deliberately uses the people it directs to the border area for its own purposes,” the Finnish government said in a statement.
The statement noted that the influx and potential for escalation “pose a serious threat to public order and national security,” testing the capacity of immigration services and increasing the risk that “criminals or radicalized persons” could be among those trying to enter the country.
Large-scale illegal immigration could also increase polarization in society and weaken citizens’ sense of security, the statement added.
Since the closures at the border last week, Markku Hassinen, deputy chief of the Finnish border guard, said that “organized” and “instrumentalized” illegal entry had continued and expanded to Finland’s most northern crossings.
The new restrictions will make it more difficult for undocumented migrants coming from Russia to seek asylum in Finland, with the Raja-Jooseppi crossing harder to reach.
Governor Andrei Chibis of the Murmansk region of Russia, which neighbors the Raja-Jooseppi crossing, said that the number of foreign citizens wishing to enter Finland through his territory was likely to increase exponentially.
Because of that, he said in a Telegram post, he introduced a “high alert regime” and a number of additional measures “to ensure the safety of our residents.”
Finland has started erecting barriers at some of the crossings, officials said, and Mr. Hassinen said that guards were prepared to respond if migrants attempted to traverse the border away from official crossings.
Frontex, the European Union’s border and coast guard agency, said on Thursday that it planned to deploy 50 officers and other staff members, along with equipment such as patrol cars, to bolster security at the crossings in Finland, which is a member of the bloc.
The agency said that the security of Finland’s eastern border was “a matter of collective European concern.”
