A total of 4,500 NATO troops alongside members of the Finnish and Swedish militaries began their annual BALTOPS exercises on Monday.
Some 140 Finnish troops from the Navy marine infantry unit Uusimaa Bridgade and a Finnish mine carrier will participate in the drills.
For the first time in the country's history, about 600 troops are taking part in landing exercises onto Finnish land.
The countries of Sweden and Finland are not members of the NATO military alliance but are taking part in the operations. Finnish troops have participated in the drills since 1993.
The exercises – which are taking place in Finland until Wednesday and will continue for several days afterwards in Baltic Sea areas – will utilise a total of some 49 ships, 61 aircraft and three submarines.
The BALTOPS exercises are held in the Baltic Sea region annually.