HELSINKI - Finland said on Tuesday that "thousands" of third-country migrants were waiting to cross the border onto its territory from Russia.

Finland closed all crossings on its 1,340 km (830 mile) border with Russia late last year amid a growing number of arrivals who lacked valid documents to enter the European Union. Helsinki accuses Moscow of funnelling migrants to the border, a claim the Kremlin has denied.

"We have information that thousands of people on the Russian side are waiting to get to Finland," Interior Minister Mari Rantanen told a news conference, adding that this represented "a threat to society".

Rantanen declined to say how Finnish authorities had obtained the information.

While Finland's forested border areas have seen freezing temperatures and deep snow during the winter months, Rantanen said she believed more migrants may seek to cross illegally as spring arrives and temperatures gradually increase.

Rantanen said existing EU legislation did not offer solutions for handling situations like the one faced by Finland.

The Finnish border authority has said more than 1,300 asylum seekers from nations including Yemen, Somalia and Syria had entered Finland from Russia between August and December last year, 900 of them in November alone. In comparison, the number before last August had averaged just one person a day.

Finland's immigration authority told Reuters in January that it had not been able to locate some 160 of the migrants and that they had probably continued to another European country.

Relations between Russia and Finland, once relatively cordial, have deteriorated sharply since Helsinki's decision to join NATO following the Russian invasion of Ukraine on Feb. 24, 2022.

The Finnish Interior Ministry said on Monday it would swiftly draft legislation to strengthen border security and combat attempts by Moscow to pressure Finland in the form of instrumentalised migration.

The government will present its proposal to parliament next month, it added. REUTERS