They are valuable for their rare earth minerals, a key component to manufacturing energy dense capacitors and batteries.
They’re also important because they are literally one of the only developed sources of rare earth minerals outside of China and not held by a Chinese corporation.
He’s asking to buy the island as an opening position before meeting with their government next week ... including trade discussions.
Wasting his time then. Denmark is part of the EU. Trade agreements are with them. If he goes there asking to buy Greenland they're just going to laugh at him.