Since his first term, President-elect Donald Trump has insisted that the United States should purchase Greenland - to the bewilderment of aides asked to investigate such a possibility, and despite repeated denials by top officials in Greenland and Denmark, of which the island is an autonomous territory, that it would ever be for sale at any price.

"Here we go again," said Malte Humpert of the Arctic Institute. "This idea remains as ludicrous as it was in 2019."