The European Union on Friday accused Russia of making a "shameful" use of migrants to put pressure on other countries, saying it had noted an increased number of undocumented asylum seekers crossing Russia's border to Finland.
Helsinki announced Thursday that is will close four of its eight border crossings with Russia from this weekend because of the increased flow of asylum seekers.
Finnish Prime Minister Prime Minister Petteri Orpo said Russia was deliberately seeking to destabilise his country in response to its NATO adhesion this year.
European Commission president Ursula von der Leyen spoke to Orpo on Thursday and said that "Russia's instrumentalisation of migrants is shameful".
EU spokesman Christian Wigand said Friday Brussels "notes an increase in arrivals of undocumented asylum seekers from the Russian Federation to Finland."
"We are closely following the situation. We are in contact with the Finnish authorities and Finnish border guards," he said.
Helsinki's ties with Moscow have deteriorated since Russia's invasion of Ukraine in February 2022. This prompted Finland to abandon decades of military non-alignment and join NATO amid concerns for its own security.
The Nordic country, which shares a 1,340-kilometre (830-mile) border with Russia, has since August seen a surge in people crossing the frontier despite not having proper documentation, primarily nationals from the Middle East and Africa, according to Finland's border guard.
Some 280 asylum seekers have arrived at the border since September, the border guard said Thursday.
"Member states have an obligation to protect the external borders, and they are the ones best place to define how to do this in practice in full compliance with fundamental rights," Wigand said.
Brussels has previously accused Russia's close ally Belarus of pushing tens of thousands of undocumented migrants across its border towards Poland and Lithuania in 2021 in retaliation for EU sanctions.
Poland in August accused Russia and Belarus of orchestrating a fresh influx of migration.