Finland said Tuesday it is considering closing its border crossings with Russia, accusing Moscow of deliberately turning a blind eye to illegal migrants.

Prime Minister Petteri Orpo said he believed Russia was allowing migrants to cross into Finland despite not having proper travel documents, suggesting it was a tactic aimed at destabilising its neighbour.

"This seems like a deliberate decision," Orpo said, adding: "The government's message is clear, we want to take care of the security of our border."

Finland shares a 1,340-kilometre (830-mile) border with Russia.

In April, Moscow warned it would take countermeasures... in tactical and strategic terms" after branding Finland's decision to join NATO as an "assault on our security".

Finnish Interior Minister Mari Rantanen told reporters Tuesday that the government parties had agreed "that the interior ministry will prepare a proposal on restriction measures under section 16 of the Border Guard Act."

"Based on observations by the Finnish Border Guard, the number of asylum seekers has grown on the eastern border in recent months," she added.

Rantanen said the numbers remained "relatively low, but have increased significantly in a short period of time."

According to officials, 39 people arrived at the southeastern border on Monday, more than the whole of last week combined when 34 asylum seekers arrived.

Russia allowed an earlier surge of people without proper travel documents to cross the border after Russia invaded Ukraine in February 2022, Helsinki said, primarily Russians and Ukrainians.

But "there have been changes to the arrivals' nationalities", Rantanen said.

Since August, an increasing number are coming from the Middle East and Africa, said Mikko Lehmus, the head of the Finnish Border Guard's risk analysis unit.

The top three nationalities crossing illegally were Iraqis, Somalis and Yemenis, Lehmus said, adding that the change began "at the end of summer".

The Nordic country of 5.5 million people is in the process of putting up a 200-kilometre fence on a section of its border with Russia, due to be completed by 2026.

At present, Finland's borders are secured primarily by light wooden fences, mainly designed to stop livestock from wandering to the wrong side.