More than 20,000 soldiers from 13 nations take part in drills lasting nearly two weeks in the northern regions of Finland, Norway and Sweden.

With over 4,000 Finnish soldiers taking part, the Norway-led Nordic Response 2024 represents the NATO newcomer’s largest ever participation in a foreign exercise, according to Finland’s military.

“For the first time, Finland will participate as a NATO member nation in exercising collective defense of the alliance’s regions,” the Finnish Defense Forces said in a statement.

The Swedish Armed Forces said about 4,500 personnel from its air force, army and navy would take part in the drill, which is being conducted in demanding Arctic winter conditions.