HELSINKI, Apr. 4 (Reuters) - Finland will indefinitely extend the closure of land border crossings with Russia and add several ports to a list where travel from its eastern neighbour is prohibited, the government said on Thursday.

Finland shut its land borders with Russia late last year amid a growing number of arrivals from countries including Syria and Somalia. It has accused Moscow of weaponising migration against the Nordic nation, an assertion the Kremlin denies.

"Finnish authorities see this as a long-term situation. We have not seen anything this spring that would lead us to conclude that the situation has changed meaningfully," Interior Minister Mari Rantanen said in a statement.
The government had said in February that the border closure was set to last until April 14.

Finland annoyed Russia last year by abandoning its long-held stance of military non-alignment and joining the NATO alliance in response to Moscow's invasion of Ukraine. The Nordic nation has also signed a bilateral defence pact with the United States.

Despite the border closure, a few asylum seekers have continued to arrive from Russia and the government believes the numbers could rise significantly with the advent of spring and a rise in temperatures.

"There are hundreds and possibly thousands of people close to Finland's border on the Russian side that could be instrumentalised against Finland," Rantanen said.

By "instrumentalised", he was referring to the alleged steering of migrants to the frontier by Moscow to raise pressure on Finland and the wider European Union over their political and military support for Ukraine.

Last month, the Finnish government floated plans for temporary legislation that would allow border authorities to block asylum seekers seeking to enter from Russia.

The government said it had decided to close three ports to leisure boating - on the Baltic Sea islands of Santio and Haapasaari, as well as at Nuijamaa on the banks of an inland lake shared by the two countries - to prevent "instrumentalised" migration from spreading as spring sets in.

"This would be dangerous to people seeking to enter Finland and would burden maritime search and rescue (operations)," the ministry said in a statement.

The Finnish border authority has said that over 1,300 asylum seekers from nations including Yemen, Somalia and Syria entered from Russia between August and December last year. Prior to this period, the numbers had averaged just one person a day.

Photo from Reuters