(Bloomberg) -- Finland decided to close the last road border crossing that had remained open on its frontier with Russia after it continued to push migrants into the Nordic country. 

New information and estimates indicated that “instrumentalized immigration” would have intensified without the decision, Prime Minister Petteri Orpo and Interior Minister Mari Rantanen told reporters on Tuesday. 

All eight road checkpoints will be closed Nov. 30 to Dec. 13, including the northernmost crossing, Raja-Jooseppi in Lapland, that’s currently the only one open. A railway crossing in Vainikkala remains open to cargo.

“This is a Russian hybrid operation, and we refuse to accept it,” Orpo said. “Russia has started it and Russia can also end it.”

Seven border stations were already shut this month over what the newest NATO member sees as a hybrid operation to push asylum seekers across the demarcation line. Finnish authorities view the operation masterminded by Moscow as a threat to its national security.

Finland’s government had warned several times the entire border would be closed should Russia continue to facilitate migrant entry. The aim is to normalize the situation on the border as soon as possible, Orpo said.

Read More: What Is Hybrid Warfare, and Is Russia Employing It?: QuickTake

Finland, which joined the North Atlantic Treaty Organization in April, guards 1,300 kilometers (800 miles) of border with Russia, the alliance’s longest stretch facing its main adversary. 

The Nordic country updated its border guard laws last year to give authorities a toolkit to counter hybrid influence activities, including an arrival of exceptionally high number of immigrants in a short period of time or what they termed the “instrumentalization of migration” by a state.

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