Denmark said on Friday it meant seriously that Greenland is not for sale, after Secretary of State Marco Rubio said U.S. President Donald Trump's interest in acquiring the island was "not a joke".

Denmark said on Monday it would spend 14.6 billion Danish kroner ($2.05 billion) boosting its military capabilities in the Arctic – a decision that comes amid continuing furor following US President Donald Trump’s renewed interest in controlling Greenland,

Trump has refused to rule out using military force to acquire the Arctic island, arguing that controlling Greenland is a “necessity” for economic security.