The emergency moves were initiated after American troops captured Venezuela’s President Maduro, which demonstrated Mr Trump’s willingness to use military force.
President Trump has made clear on several occasions that he wants Greenland – a self-governing Danish territory – to become part of the United States.
He has refused to rule out using military force to take the territory.
But a new report appears to show Copenhagen’s willingness to match fire with fire if the US did decide to act.
Following Mr Trump’s re-election in 2025, Denmark reportedly sought confidential talks with European allies to shore up support against any annexation attempt.
Europe was keen to show how seriously it took defending the island and formed plans to send soldiers and military hardware to Greenland later in 2026.
DR’s report, based upon the testimonies of 12 key sources at the top of Denmark’s government and military, claims that everything changed following the US invasion of Venezuela on January 3.
Days after this, Mr Trump said the US “needs Greenland for national security”, adding that he was “very serious” about it.
This sparked a rapid European response, with Danish, French, German, Norwegian and Swedish soldiers flying to the territory.
Danish fighter jets and a French naval vessel then followed as part of a larger, well-publicised and announced, main force.
It all formed part of Operation Arctic Endurance, a Danish-led joint military exercise to prepare for and deter a possible US invasion, DR claims.
Denmark hoped that having soldiers with as many different flags on their arms as possible would deter US action, as it would mean Washington would have had to commit to major hostile action against multiple fellow NATO allies.
Danish soldiers were also reportedly given live ammunition and permission to engage.
These moves appeared to have worked, as Mr Trump said the US “won’t use force” to take Greenland at the World Economic Forum on January 21.
But he reiterated that the US was “unstoppable”.