BERLIN — On Sunday, eight European nations criticized U.S. President Donald Trump’s decision to impose a 10% tariff in retaliation for their objection to American influence over Greenland. The countries warned that such threats could destabilize transatlantic relations and lead to a perilous decline in diplomacy.

This unified response from some of the United States’ closest allies suggests a shift in the recent diplomatic friction concerning sovereignty and security issues, coming less than a day after Trump’s remarks.

The statement marked the most assertive criticism from European allies since Trump’s return to the White House nearly a year ago. Previously, European nations have largely employed diplomacy and appeasement, even while advocating for an end to the conflict in Ukraine. However, Sunday’s declaration, alongside European troops participating in a Danish military exercise in Greenland, indicates a strategic pivot.

Denmark, Norway, Sweden, France, Germany, the United Kingdom, the Netherlands, and Finland issued a rare collective statement, emphasizing that their military presence in Greenland for the “Arctic Endurance” operation is “non-threatening.”

Standing in solidarity with Denmark and Greenland

Trump’s announcement on Saturday potentially challenges U.S.-European alliances. He implied that the tariffs were intended to pressure discussions about Greenland’s status, a semi-autonomous region of Denmark, deemed vital to U.S. security interests.

In response, the group declared, “We fully support the Kingdom of Denmark and the Greenlandic people. As part of the dialogue initiated last week, we are prepared to discuss based on sovereignty and territorial integrity principles. Tariff threats jeopardize transatlantic ties and could lead to a dangerous escalation.”

There are immediate questions about how the White House could try to implement the tariffs because the European Union is a single economic zone in terms of trading. It was unclear, too, how Trump could act under U.S. law, though he could cite emergency economic powers that are currently subject to a U.S. Supreme Court challenge.

EU foreign policy chief Kaja Kallas said China and Russia will benefit from divisions between the U.S. and Europe. She added in a post on social media: “If Greenland’s security is at risk, we can address this inside NATO. Tariffs risk making Europe and the United States poorer and undermine our shared prosperity.”

Europe has been trying to keep Trump on its side to ensure U.S. support for Ukraine, including Washington sharing intelligence with Kyiv and its involvement in security guarantees if a peace agreement is reached with Russia.

Rasmus Sndergaard, a senior researcher at the Danish Institute for International Studies, called Trump’s announcement “unprecedented” because tariff threats normally stem from trade disagreements, not territorial disputes between allies.

“That’s of course why we’re seeing the response from European countries saying ‘enough is enough,’” he told The Associated Press. “I think there’s in part probably a strategic calculation, of course, from the governments in these countries that if you give in to Trump on this, what will be the next thing? And at some point you have to sort of push back.”

Sndergaard also said Trump leveled the playing field for Europe with the tariff threat. Europeans cannot compete militarily, but the EU can wield an economic weapon through reciprocal tariffs.

“The EU has the ability to really strike back with force if they want to, and it will hurt European economies,” he said. “It will hurt American economies. The challenge for Trump is he has midterms coming up and it’s not going to help him if the U.S. goes into more of an economic recession or more of a economic turmoil than is already the case.”

Meanwhile, NATO Secretary General Mark Rutte wrote on social media Sunday that he’d spoken with Trump. Rutte has been criticized in recent days for largely sidestepping questions about Trump and Greenland and any NATO tensions over the island.

“We will continue working on this, and I look forward to seeing him in Davos later this week,” Rutte said.

U.K. Prime Minister Keir Starmer also spoke to Trump and told him that “applying tariffs on allies for pursuing the collective security of NATO allies is wrong,” a Downing Street spokeswoman said. That call followed conversations with Rutte, Danish Prime Minister , Mette Frederiksen, and European Commission President Ursula von der Leyen.

Trump’s move was also panned domestically.

U.S. Sen. Mark Kelly, a former U.S. Navy pilot and Arizona Democrat, said Trump’s threatened tariffs on U.S. allies would make Americans “pay more to try to get territory we don’t need.”

“Troops from European countries are arriving in Greenland to defend the territory from us. Let that sink in,” Kelly wrote on social media. “The damage this President is doing to our reputation and our relationships is growing, making us less safe. If something doesn’t change we will be on our own with adversaries and enemies in every direction.”

Former U.S. Vice President Mike Pence said he supports the United States ultimately owning Greenland, but not how Trump is trying to accomplish it.

He said he had concerns whether Trump had the constitutional authority to impose unilateral tariffs on NATO allies, as well as about a threat of a military invasion. Trump’s current position threatens “to fracture that strong relationship, not just with Denmark, but with all of our NATO allies,” Pence said on CNN’s “State of the Union.”

Populist allies of Trump criticize the tariff threat

Six of the countries targeted are part of the 27-member EU, which operates as a single economic zone in terms of trading. It was not immediately clear if Trump’s tariffs would impact the entire bloc. EU envoys scheduled emergency talks Sunday evening to determine a potential response.

The tariff announcement also drew blowback from Trump’s populist allies in Europe.

Italy’s right-wing premier, Giorgia Meloni, considered one of Trump’s closest allies on the continent, said she had spoken to him about the tariffs, which she described as “a mistake.”

The deployment to Greenland of small numbers of troops by some European countries was misunderstood by Washington, Meloni said, adding it was not a move against the U.S. but aimed to provide security against “other actors” that she didn’t identify.

Jordan Bardella, president of Marine Le Pen’s far-right National Rally party in France and a European Parliament lawmaker, posted that the EU should suspend last year’s tariff deal with the U.S., describing Trump’s threats as “commercial blackmail.”

Trump also achieved the rare feat of uniting Britain’s main political parties – including the hard-right Reform UK party – all of whom criticized the tariff threat.

“We don’t always agree with the U.S. government and in this case we certainly don’t. These tariffs will hurt us,” said Reform UK leader Nigel Farage, a longtime champion and ally of Trump. His social media post stopped short of criticizing Trump’s designs on Greenland.

Also in London on Sunday, a heckler yelled “leave Greenland alone!” while Vanessa Williams sang “The Star-Spangled Banner” before tipoff of an NBA game between the Memphis Grizzlies and the Orlando Magic. The outburst drew scattered laughs and applause.

Lawless reported from London and Burrows reported from Nuuk, Greenland. John Leicester in Paris, Lorne Cook in Brussels, Barry Hatton in Lisbon, Portugal, Aamer Madhani in Washington, Edith M. Lederer in New York, and Josh Boak in West Palm Beach, Florida, contributed.