U.S. President Donald Trump said on Tuesday that there was "no going back" on his goal of controlling Greenland, refusing to rule out taking the Arctic island by force and lashing out at NATO allies as European leaders struggled to respond.

However, later, Trump, who is due to join European leaders at the World Economic Forum in Switzerland, told a news conference that he thought, "We will work something out where NATO is going to be very happy and where we're going to be very happy."

Trump's ambition to wrest sovereignty of Greenland from fellow NATO member Denmark has threatened to unravel the alliance that has underpinned Western security for decades.

It has also threatened to reignite a trade war with Europe that rattled markets and companies last year, though Trump's Treasury Secretary, Scott Bessent, pushed back against what he called "hysteria" over Greenland.

In a Truth Social post on Tuesday, after speaking with NATO Secretary General Mark Rutte, Trump said, "Greenland is imperative for National and World Security. There can be no going back – On that, everyone agrees!"

Asked later how far he was willing to go to acquire Greenland, Trump told reporters at the White House, "You'll find out."

But Trump said he had many meetings scheduled in Greenland, Switzerland, and added: "I think things are going to work out pretty well."

Read more: 

U.S. ambition for Greenland further deepens transatlantic trust deficit

Greenland's leadership has repeatedly stated that the vast but sparsely populated island is not for sale.

Danish Prime Minister Mette Frederiksen said she would not yield to Trump's demands or abandon Greenland.

"The American president has unfortunately not ruled out the use of military force, and therefore the rest of us cannot rule it out either," she told reporters.

An agreement on sharing responsibility for the security of the Arctic and the North Atlantic could offer a way out of the standoff, Lithuanian President Gitanas Nauseda told Reuters at the World Economic Forum in the Swiss ski resort of Davos.

European leaders took to the stage in Davos, attempting to project the continent's strength, though it was not immediately clear how the European Union would eventually respond.

"We do believe that we need more growth, we need more stability in this world, but we do prefer respect to bullies," Macron told the meeting in Davos.

Some emphasized the importance of reducing Europe's security dependence on the United States. European Commission President Ursula von der Leyen described a "seismic change" that made it necessary to build a "new form of European independence."

(With input from agencies)