Finland joined the North Atlantic Treaty Organization earlier this month after putting in an application that was triggered by Russia’s full-scale invasion of its neighbor, Ukraine. In addition to gaining NATO’s Article 5 collective security guarantees, it has also increased defense spending and procurement of weapons and ammunition.

The project aims to improve surveillance and security, and follows in the footsteps of peers such as Lithuania, Latvia and Poland that are setting up barriers. The Finnish fence won’t span the entire 1,343-kilometer length of the demarcation, but instead the plan is to cover the riskiest spots, especially around crossing points, against targeted mass entry.

Should Finland face “instrumental or otherwise widespread illegal entry,” the fence under construction will be an “essential complement,” the Border Guard said. Part of the project will be to build pontoon roads out of concrete for crossing wetlands.