"The government proposal would make it possible in future to bring a nuclear weapon into Finland, or to transport, deliver or possess one in Finland, if it is connected to the military defence of Finland," Defence Minister Antti Hakkanen told reporters.

"In all other situations than these grounds for exception, the import, transport, delivery and possession of nuclear explosives would continue to be prohibited," he said.

Hakkanen said Finland's and Europe's security environment had "fundamentally and significantly changed and deteriorated" following Russia's full-scale invasion of Ukraine in 2022.

The Nordic country dropped decades of military non-alliance to join NATO in April 2023.

But Helsinki was only able to familiarise itself with NATO's nuclear defence after it became a full member because it is classified information, Hakkanen said.

Finland's proposed policy change requires amendments to its Nuclear Energy Act and the criminal code.

The right-wing coalition, which holds a majority in parliament, said its proposal had been sent around for consultation until April 2, and hoped the new law would enter into force as soon as possible.