Public opinion in Finland has sung behind membership after the Russian invasion of Ukraine began in February. A Russian military Mi-17 helicopter flew 2-3 miles inside the Finnish border after 10.30am this morning (7.30am GMT), according to the country’s Ministry of Defence.
They said: “The aircraft type is a Mi-17 helicopter and the depth of the suspected violation is about four to five kilometres.”
A Russian politician warned last month Finland would be asking for “the destruction of their country”.
Senator Vladimir Dzhabarov said the move is a “terrible tragedy”.
Russia previously violated Finnish airspace on April 8 for the first time since the start of the conflict in Ukraine.
It comes as a Finnish nuclear provider terminated a contract with Russian state energy firm Rosatom for the delivery of a power plant.
Fennovoima warned the conflict in Ukraine “has worsened the risks for the project”, which was due to generate about 10 percent of Finland’s electricity needs.
As well as public opinion a majority of Finnish MPs are now in favour of NATO membership.
President Sauli Niinisto is set to announce his personal stance on the issue on May 12.
Even if Stockholm submits an application it could take a year for it to obtain full membership as existing NATO members would have to approve their candidacy.
The Swedish Foreign Minister Ann Linde told Swedish television from Washington that she was satisfied with the assurances given by US Secretary of State Antony Blinken.
She said: “Naturally, I’m not going to go into any details, but I feel very sure that now we have an American assurance.
“However, not concrete security guarantees, those you can only get if you are a full member of NATO.
“They would mean that Russia can be clear that if they direct any kind of negative activities against Sweden, which they have threatened, it would not be something that the US would just allow to happen … without a response.”