NATO will launch its biggest military exercises in decades next week with around 90,000 personnel set to take part in months of drills aimed at showing the alliance can defend all of its territory up to its border with Russia, top officers said Thursday.

The exercises come as Russia’s war on Ukraine bogs down. NATO as an organization is not directly involved in the conflict, except to supply Kyiv with non-lethal support, although many member countries send weapons and ammunition individually or in groups, and provide military training.

The exercises – dubbed Steadfast Defender 24 – “will show that NATO can conduct and sustain complex multi-domain operations over several months, across thousands of kilometers (miles), from the High North to Central and Eastern Europe, and in any condition,” the 31-nation organization said.

Troops will be moving to and through Europe until the end of May in what NATO describes as “a simulated emerging conflict scenario with a near-peer adversary.” Under NATO’s new defense plans, its chief adversaries are Russia and terrorist organizations.

“The alliance will demonstrate its ability to reinforce the Euro-Atlantic area via transatlantic movement of forces from North America,” NATO’s Supreme Allied Commander, U.S. General Christopher Cavoli, told reporters. Cavoli said it will demonstrate “our unity, our strength, and our determination to protect each other.”