Greenland is an autonomous territory of Denmark 90% populated by Greenlandic Inuit people. Greenland's current coalition government, which manages domestic affairs, includes as major members the Inuit Ataqatigiit & Siumut parties, both dem socialist, pro-independence. It's not going to be "bought."
"Secretary of State Marco Rubio told lawmakers that recent administration threats against Greenland didn’t signal an imminent invasion and that the goal is to buy the island from Denmark, according to people familiar with the discussions."
wsj.com
Exclusive | Rubio Tells Lawmakers Trump Aims to Buy Greenland, Downplays Military Action
The secretary of state said the White House is using rhetoric to pressure Denmark into negotiations.