Greenland is not for sale and the idea of selling it to the United States is absurd, Denmark's prime minister said on Sunday after an economic adviser to President Donald Trump confirmed the U.S. interest in buying the world's largest island.

"Greenland is not for sale. Greenland is not Danish. Greenland belongs to Greenland. I strongly hope that this is not meant seriously," Danish Prime Minister Mette Frederiksen told the newspaper Sermitsiaq during a visit to Greenland.

Trump's is due to visit Copenhagen early next month, when the Arctic will be on the agenda in meetings with Frederiksen and Prime Minister Kim Kielsen of Greenland, an autonomous Danish territory.

White House economic adviser Larry Kudlow on Sunday confirmed media reports earlier in the week that Trump had privately discussed with his advisers the idea of buying Greenland.

"I don't want to predict an outcome, I'm just saying the president, who knows a thing or two about buying real estate, wants to take a look at a Greenland purchase," Kudlow told Fox News.

Kudlow said the situation was "developing" and noted that U.S. President Harry Truman also had wanted to buy Greenland.

"And Denmark owns Greenland, Denmark is an ally, Greenland is a strategic place, up there. And they've got a lot of valuable minerals," Kudlow added.