Denmark would need to offer Greenland to the UK first before the island could be sold to Donald Trump, it has emerged. An agreement dating back to 1917 means Britain has first refusal on the Arctic island if current owners Denmark decide to sell it, according to Tom Høyem, Copenhagen’s representative in Greenland from 1982 to 1987.

During last week's tense call with the Danish premier, Trump insisted he was serious about taking over Greenland, the Financial Times reported, raising fears about the future of trans-Atlantic relations.