Aiming to put his mark on the world map, President Donald Trump has talked to aides and allies about buying Greenland for the U.S. A Trump ally told Thursday that the president had discussed the purchase but was not serious about it. And a Republican congressional aide said Trump brought up the notion of purchasing Greenland in conversations with lawmakers enough times to make them wonder, but they have not taken his comments seriously. Both spoke on condition of anonymity to discuss private conversations.

Still, it wouldn’t be the first time an American leader tried to buy the world’s largest island, an autonomous territory of Denmark.In 1946, the U.S. proposed to pay Denmark $100 million to buy Greenland after flirting with the idea of swapping land in Alaska for strategic parts of the Arctic island.