LONDON — The leaders of all 27 European Union nations will meet for an “extraordinary meeting” later this week, European Council President Antonio Costa said on Sunday, in response to U.S. President Donald Trump’s escalating pressure campaign to acquire Greenland.

Costa said he had called the meeting due to the “significance of recent developments.”

European leaders are mobilizing after Trump on Saturday announced a 10% tariff to be imposed on all goods sent to the U.S. from eight NATO nations — Denmark, Norway, Sweden, France, Germany, the U.K., the Netherlands and Finland — that recently sent small contingents of troops to Greenland to take part in military exercises there.

Costa said recent conversations with European leaders had reconfirmed their “strong commitment” to international law, Arctic security through NATO and solidarity with Denmark and Greenland in the face of Trump’s continued effort to acquire the Arctic island.

European leaders also agreed that “tariffs would undermine transatlantic relations and are incompatible with the EU-U.S. trade agreement,” Costa said, noting the bloc’s “readiness to defend ourselves against any form of coercion” and to engage “constructively with the US on all issues of common interest.”

An EU Council spokesperson confirmed to ABC News that the summit would be an in-person meeting in Brussels.

Trump said the new tariffs will come into force on Feb. 1 and will increase to 25% on June 1. The president said the measures would remain in place until the U.S. is able to purchase Greenland.

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.

Trump’s new tariffs raise the risk of a fresh transatlantic trade war. A French official confirmed to ABC News on Monday that French President Emmanuel Macron “will request the activation of the EU’s anti-coercion instrument in the event of new U.S. tariffs.”

That mechanism, colloquially known as the bloc’s “trade bazooka,” would allow the EU to impose severe restrictions on U.S. goods and services. Among the available measures would be restrictions on U.S. investment in EU nations, blocks on access to public procurement schemes and limits on intellectual property protections.

Trump has repeatedly suggested that U.S. sovereignty over the world’s largest island is necessary to ensure American security and blunt Chinese and Russian influence in the Arctic region. On Sunday, the president again claimed that only the U.S. can ensure the security of Greenland.

A 1951 defense agreement grants the U.S. military access to Greenland. Danish politicians have repeatedly expressed willingness to work with Washington to expand the American and NATO presence there.

Danish officials have also sought to head off concerns about the supposed vulnerability of the Arctic. Last year, Copenhagen announced a $6.5 billion Arctic defense package in response to U.S. criticism that it had failed to adequately protect Greenland.

But such steps do not appear to have deterred Trump, who has said he would consider taking Greenland by force if other means to acquire the land fail.

Indeed, it was the recent deployment of more NATO forces to the Arctic territory that prompted Trump to threaten a new raft of tariffs. The troops traveled to Greenland to take part in the Danish-led Operation Arctic Endurance.

Danish Defense Minister Troels Lund Poulsen and Greenlandic Foreign Minister Vivian Motzfeldt are scheduled to visit NATO’s headquarters in Brussels on Monday for a previously planned meeting with the alliance’s Secretary General Mark Rutte, NATO said in a press release.

On Monday, British Prime Minister Keir Starmer urged “calm discussion” between allies. “The security of Greenland matters and it will matter more as climate change reshapes the Arctic,” he said, noting the need for “greater attention, greater investment and stronger collective defense.”

“The United States will be central to that effort, and the U.K. stands ready to contribute fully alongside our allies through NATO,” Starmer said, adding that any decisions about the territory’s future should be left to Greenlanders and Danes.

Trump’s use of tariffs against allies, Starmer continued, “is completely wrong. It is not the right way to resolve differences within an alliance. Nor is it helpful to frame efforts to strengthen Greenland’s security as a justification for economic pressure.”

ABC News’ Victoria Beaule, Tom Soufi Burridge and Kevin Shalvey contributed to this report.