United States President Donald Trump has threatened to impose sweeping tariffs on European allies resisting his push for American control of Greenland, declaring he would act “100 per cent” if opposition continues.

The threat has deepened tensions between Washington and key NATO partners, with Denmark insisting that the semi-autonomous Arctic territory is not for sale and cannot be acquired through intimidation.

European governments rallied behind Greenland’s sovereignty on Monday. Denmark’s foreign ministry warned that any attempt by the US to claim the territory through economic or military pressure would violate international law.

Britain’s Foreign Secretary, Yvette Cooper, echoed the position, saying the future of Greenland must be determined solely by its people and Denmark.

Trump, however, maintained a hard line. Speaking to reporters, he refused to rule out the use of force and confirmed plans to impose tariffs on goods from the United Kingdom and seven European NATO members.

In a post on Truth Social early Tuesday, the US leader disclosed that he had held “a very good telephone call” with NATO Secretary-General Mark Rutte and agreed to a multilateral meeting in Switzerland later this week.

“Greenland is imperative for national and world security. There can be no going back. On that, everyone agrees!” Trump wrote.

He announced that Britain would face a 10 per cent tariff on all exports to the US from February 1, rising to 25 per cent from June 1, until Washington secures a deal to purchase Greenland from Denmark. Similar measures, he said, would apply to Denmark, Norway, Sweden, France, Germany, the Netherlands and Finland.

Asked directly if he would carry out the threat, Trump replied: “I will, 100 per cent.” On whether military force was an option, he said: “No comment.”

He also urged European allies to concentrate on the Russia-Ukraine war rather than opposing his Greenland agenda.

Copenhagen reacted sharply, warning that any US military action in Greenland would undermine NATO unity. Danish Foreign Minister Lars Løkke Rasmussen described tariff threats as “not the way forward.”

“You can’t threaten your way to ownership of Greenland. I have no intention of escalating this situation,” Rasmussen said.

Germany’s Chancellor Friedrich Merz cautioned that a trade war would benefit no one, expressing hope for dialogue with Trump on the sidelines of the World Economic Forum in Davos.

European Union foreign policy chief Kaja Kallas said the bloc would defend its interests, adding: “Sovereignty is not for trade.”

EU leaders are scheduled to hold an emergency summit in Brussels on Thursday to forge a collective response to the escalating dispute.