As one of Finland's dozens of reserve runways, the empty highway near the town of Joutsa, hosted an annual air force exercise with F/A-18 Hornets taking off and landing.

The manoeuvres come amid heightened geopolitical tensions due to the war in Ukraine, and as Finland has moved to join NATO.

"The exercise went well. The objectives were achieved ahead of schedule," Vesa Mantyla, the officer in charge of the exercise, told AFP.

Starting Monday, the exercise closed off a section of Finland's main highway that connects Helsinki with the country's north.

The goal of the exercise was to train a new batch of the Nordic country's fighter pilots to take off and land on these rural runways.

With over 70 percent of Finland's area covered by forest, the highest percentage in Europe, it has adapted its military to take advantage of its geography.

In wartime, part of the Nordic country's fleet of fighter jets would operate from these forest-covered ad-hoc bases.

"As we have seen in Ukraine, ballistic and cruise missiles are used a lot on fixed targets," Mantyla explained, noting his country's lengthy shared border of some 2,000 kilometres (1250 miles) border with Russia.