LONDON — The escalating showdown between the U.S. and its NATO allies over the fate of Greenland looks set to be a dominant topic of conversation as leaders gather at this week’s World Economic Forum event in Davos, with U.S. President Donald Trump again declaring on Monday that American ownership of the Arctic island is “imperative.”

Trump said in a post to social media that, following a phone call with NATO Secretary-General Mark Rutte, “I agreed to a meeting of the various parties in Davos, Switzerland. As I expressed to everyone, very plainly, Greenland is imperative for National and World Security. There can be no going back — On that, everyone agrees!”

Greenland is a self-governing territory of the Kingdom of Denmark. Trump first raised the prospect of acquiring the minerals-rich island in his first term. Danish and Greenlandic politicians have repeatedly rebuffed such proposals.

European leaders, meanwhile, continued to push back on Trump’s ambitions and publicize their coordination efforts on the issue.

European Commission President Ursula von der Leyen said in a post to X that she met with a bipartisan congressional delegation to discuss both Russia’s war in Ukraine and recent tensions around Greenland.

Von der Leyen said she “addressed the need to unequivocally respect the sovereignty of Greenland and of the Kingdom of Denmark. This is of utmost importance to our transatlantic relationship.”

The European Union, she said, “remains ready to continue working closely with the United States, NATO, and other allies, in close cooperation with Denmark, to advance our shared security interests.”

“We also discussed transatlantic trade and investment. They are a major asset for both the EU and US economies. Tariffs run counter to these shared interests,” von der Leyen wrote.

Danish and Greenlandic ministers traveled on Monday to Brussels to meet with NATO chief Rutte.

Danish Defense Minister Troels Lund Poulsen said afterward that the Greenland issue poses challenges “fundamentally to Europe and, for that matter, also the future of NATO.” Poulsen said Rutte is “very aware of the difficult situation.”

Greenlandic Foreign Minister Vivian Motzfeldt said the meeting “achieved some important things with regard to security in the Arctic.” She added, “It is important to know how to work with security in the Arctic. That is why we are now carrying out various exercises.”

Denmark’s Foreign Minister Lars Lokke Rasmussen, meanwhile, was in the U.K. on Monday to meet with his counterpart in London. “In turbulent times, close allies are crucial — Denmark and the UK stand close together,” Rasmussen wrote on X. “We agree on the need for stronger NATO engagement in the Arctic and closer security cooperation.”

Trump has suggested that U.S. sovereignty over Greenland is necessary to ensure American security and blunt Chinese and Russian influence in the Arctic region. A 1951 defense agreement already grants the U.S. military access to Greenland, but Trump has suggested the deal is inadequate.

Denmark and its European allies have sought to ease concerns about the supposed vulnerability of the Arctic through more military spending and by sending small contingents of troops to Greenland last week. 

But Trump interpreted the deployments as a provocation, and announced new 10% tariffs on all goods from the eight nations — Denmark, Norway, Sweden, France, Germany, the U.K., the Netherlands and Finland — that sent troops.

European leaders hit back at Trump’s decision and said the move threatened a new transatlantic trade war.

ABC News’ Will Gretsky, Kevin Shalvey and Meg Mistry contributed to this report.