Mike Pence and other prominent Republicans have publicly criticised the president's aggressive tactics, warning they risk fracturing NATO alliances and are potentially unconstitutional.
European nations, including Denmark, the UK, and France, have condemned Trump's approach, with France's President Macron comparing the threats to Russia's actions in Ukraine.
The White House recently met with Danish and Greenlander emissaries, which Europeans described as unproductive, leading to Trump announcing a 10 per cent tariff on Denmark.
Both American public opinion and Greenlanders largely oppose the acquisition, with polls showing minimal support for the plan in either region.