It's a point for defense against Russia, I think is the main argument (besides the rare metal one).
Take a look at a map of the world from the point of view of North Pole, and you'll understand why warmongers think it's an important point to hold: https://i.imgur.com/LE8DKGR.png
This argument has been rebuked over and over again. Denmark and the USA already have an agreement allowing the USA to establish military bases on Greenland [1]. There used to be a lot of USA military bases on Greenland and currently there is but one: Pituffik Space Base.
Take a look at a map of the world from the point of view of North Pole, and you'll understand why warmongers think it's an important point to hold: https://i.imgur.com/LE8DKGR.png