The European Union's top official did not hold back in her warnings about President Donald Trump's threat to impose fresh tariffs on countries opposing his push for the U.S. to acquire Greenland, a semiautonomous Danish territory.

European Commission President Ursula von der Leyen called Trump's threats "a mistake" and questioned U.S. trustworthiness, saying that the EU-U.S. trade deal from July had to "mean something."

"Arctic security can only be achieved together. This is why the proposed additional tariffs are a mistake, especially between long-standing allies. The EU and U.S. have agreed to a trade deal last July. And in politics as in business — a deal is a deal. And when friends shake hands, it must mean something," Von der Leyen said.

"We consider the people of the United States not just our allies, but our friends. And plunging us into a dangerous downward spiral would only aid the very adversaries we are both so committed to keeping out of the strategic landscape," she added, vowing the EU's response would be "unflinching, united and proportional."

French President Emmanuel Macron also addressed the issue at Davos, saying the tariffs could force the EU to use its anti-coercion mechanism against the U.S. "for the very first time," Scott Bessent said U.S. relations with Europe remain strong and encouraged trading partners to "take a deep breath," the AP reported.

Leaders from Denmark, Finland, France, Germany, the Netherlands, Norway, Sweden and the U.K. issued a joint statement on Tuesday, affirming their commitment as NATO members to "strengthening Arctic security as a shared transatlantic interest." They also expressed their solidarity with Denmark and Greenland.

"Tariff threats undermine transatlantic relations and risk a dangerous downward spiral. We will continue to stand united and coordinated in our response. We are committed to upholding our sovereignty," the statement read.

Some European nations recently tried to flex their muscles with a brief troop deployment to Greenland. France, Germany, Sweden and Norway participated in a two-day exercise to bolster the Danish territory's defenses amid Trump's threats. Germany deployed a reconnaissance team of 13 personnel, France sent 15 mountain specialists and Sweden, Norway and Britain sent three, two and one officers, respectively, according to Reuters.

In text messages that Trump published on Truth Social, Macron suggested a meeting of the Group of Seven (G-7) nations in Paris after the conference in Davos. The AP reported that an official close to Macron confirmed the authenticity of the text exchange. As of Jan. 20, no such meeting had been announced.

Fox News Digital reached out to the White House for comment.

The Associated Press and Fox News Digital's Greg Norman-Diamond and Gillian Turner contributed to this report.