Swedish armed forces joined NATO for exercises on Monday, contributing troops, helicopters and fighter jets as the alliance carries out its largest set of military drills since the end of the Cold War.

Sweden is poised to join NATO, possibly within days, after gaining the final outstanding ratification last week.

The exercises — involving over 20,000 troops from more than a dozen countries — are taking place in a high north being transformed by the accession of Sweden and Finland, who turned their backs on long histories of nonalignment after Russia invaded Ukraine two years ago.