Organised by Denmark, the "Arctic Light 2025" exercise brings together more than 550 troops from NATO allies Denmark, France, Germany, Norway and Sweden.

"The current security situation requires us to significantly strengthen the armed forces' presence in the Arctic and North Atlantic," Danish Defence Minister Troels Lund Poulsen said in a statement.

Since returning to the White House in January, Trump has repeatedly said the United States needs the strategically located, resource-rich island for security reasons, which has sparked diplomatic tensions with Denmark.

The United States, which operates an airbase in the northern part of the territory, has sharply criticised Denmark for not sufficiently investing in Greenland's defence.

For Lund Poulsen, the Arctic Light 2025 exercise, coordinated with the Greenlandic government, "is a good example of our common commitment to strengthening the armed forces' ability to address threats in the Arctic."

In late August, Danish broadcaster DR reported that at least three Americans linked to President Donald Trump had conducted influence operations across the Arctic territory.