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.

Donald Trump insisted he was serious in his determination to take over Greenland in a fiery telephone call with Denmark’s prime minister, according to senior European officials.