European Union members are meeting in an emergency session at Brussels on Sunday to determine how to respond to President Trump’s latest threat to impose new tariffs against European allies that conduct security exercises on Greenland.

The debate comes amid a uniformly negative response from European countries to Mr. Trump’s Saturday threat to charge an additional 10 percent in tariffs beginning on February 1 on goods arriving to America from Denmark, Norway, Sweden, France, Germany, the United Kingdom, the Netherlands, and Finland if Denmark does not agree to sell Greenland to the United States. He said the tariffs would increase to 25 percent by June. 

“We want to cooperate, and it is not we who are seeking conflict,” the prime minister of Denmark, Mette Frederiksen, said Sunday after the European partners issued a joint statement. “Europe won’t be blackmailed.” 

Earlier in the day, the partners, who had been conducting security exercises at Nuuk under the NATO banner, said they are ready to support the strategically significant nation from external threats, but do not support giving it over to the United States. They also said the president’s tariff threats “undermine transatlantic relations and risk a dangerous downward spiral.”

“We stand in full solidarity with the Kingdom of Denmark and the people of Greenland. Building on the process begun last week, we stand ready to engage in a dialogue based on the principles of sovereignty and territorial integrity that we stand firmly behind,” reads the statement from the eight nations that were conducting the exercises.

The statement follows an “Arctic Endurance” exercise in Greenland, which had already been coordinated with the Danish government prior to Mr. Trump’s Saturday announcement of a 10 percent tariff on countries that send military forces to Greenland.

Despite the defiant comments, 15 German troops who had been at Nuuk for the exercises departed the nation on Sunday, two days after their arrival. The German newspaper Bild reported that the order reversed a Saturday expectation that the soldiers would remain in Greenland longer than originally planned. A spokesman for Bundeswehr’s Operational Command told the paper that the reconnaissance exercises were complete and an evaluation would be conducted in Germany.  

Mr. Trump has said Greenland is essential for defense from Russia and China, whose Arctic ambitions threaten American security and economic interests. Greenland is also rich with minerals that the United States needs to remain technologically competitive.

An American business executive and philanthropist, Arnie Bellini, who is a big supporter of President Trump, tells The New York Sun that the vast quantity of rare earth minerals are worth buying the entire land mass rather than paying for licensing from the Danish government.

“Let’s just call it what it is, OK? There’s a bunch of natural resources that no one’s touching there, under ice. We need the rare rare earth minerals that are in Greenland and there’s plenty of them up there,” says Mr. Bellini, adding that he is confident Greenland will become an American territory.

“We’re going to end up making a deal with Denmark, and we’re gonna say, ‘Look, you’re gonna be our special defense. We will do special defense for you if you will sell us Greenland, OK,’” he tells the Sun. “And for that, we are going to be able to protect the Arctic Circle approach of Russia and China towards the Western Hemisphere.”

Speaking on NBC’s “Meet the Press” Sunday, the president’s treasury secretary, Scott Bessent, said annexing Greenland will help America dispel future conflicts. “The national emergency is avoiding a national emergency,” he said. “This is a geopolitical decision, and he is able to use the economic might of the U.S. to avoid a hot war.”

He added that he believes “the Europeans will understand that this is best for Greenland, best for Europe and best for the United States.”

Opinions are mixed about options the Europeans will take. As some call for closed door diplomacy, others are urging the European Parliament to kill a deal the president negotiated with European Commission President Ursula von der Leyen last July, which created a 15 percent tariff framework and required the European Union to make massive purchases and investments in the United States. The deal was a framework and not a treaty so is based on amicable negotiations.

Democrats in Congress were not much more charitable about Mr. Trump’s plans than the Europeans. “The president is lying to the American people when he says this is about security,” Senator Chris Van Hollen said on ABC’s “This Week” Sunday morning. “This is not about security … This is about a land grab.” Donald Trump wants to get his hands on the minerals and other resources of Greenland, just like the real reason he went into Venezuela had nothing to do with stopping drugs from coming.”