Why does Trump want to take over? How big is Greenland compared to the United States? What you need to know about the autonomous territory of Denmark.

"Greenland never has been for sale and never will be for sale," Aaja Chemnitz, one of two MPs in the Danish parliament representing Greenland, told CNBC.

President Donald Trump said Sunday that the United States will take Greenland "one way or another, and Europe is stepping up in defense.