The proposal, if approved, would mean the number of reservists in the NATO member would reach one million by 2031 -- an increase of 125,000.

Finns currently remain part of the reserve until the age of 50 for enlisted soldiers or 60 for non-commissioned officers and reserve officers.

"Finland's defence capability is based on general conscription, a trained reserve and a strong will to defend the country," Defence Minister Antti Hakkanen said in a statement.

"By raising the maximum age of reservists we are giving more people the possibility to participate in national defence," he said.

All Finnish men have to complete military service from the age of 18, and about 900,000 conscripts have already had military training.

The increase in numbers would happen over the next five years, as those who reach the age of 60 become liable to serve for a further five years.

The defence ministry has put the proposal out for consultation until the end of next month before it is submitted to parliament.

"This is proof for NATO allies that Finland did not pause when it joined NATO but takes the strengthening of national defence very seriously," Hakkanen told public broadcaster Yle.

Finland shares a 1,340-kilometre (830-mile) border with Russia and ended decades of military non-alignment by joining NATO in April 2023, just over a year after Russia's invasion of Ukraine.

Helsinki closed its eastern border with Russia in December 2023, suspecting Moscow of orchestrating the arrival of migrants to destabilise the country.