Trump vowed on Saturday to implement a wave of increasing tariffs on EU members Denmark, Sweden, France, Germany, the Netherlands and Finland, along with Britain and Norway, until the United States is allowed to buy Greenland, escalating a row over the future of Denmark's vast Arctic island.
All the countries, already subject to tariffs of 10 per cent and 15 per cent, have sent small numbers of military personnel to Greenland.
Cyprus, holder of the rotating six-month EU presidency, summoned ambassadors to an emergency meeting in Brussels on Sunday, which EU diplomats said was due to start at 5pm local time.
A source close to French President Emmanuel Macron said he was working to coordinate a European response and was pushing for activation of the Anti-Coercion Instrument, which could limit access to public tenders in the bloc or restrict trade in services in which the US has a surplus with the EU.
In social media posts late on Saturday, Bernd Lange, the German Social Democrat who chairs the European Parliament's trade committee, and Valerie Hayer, head of the centrist Renew Europe group, echoed his call, as did Germany's engineering association on Sunday.
However, some EU diplomats said now was not the time to escalate the situation.
Italian Prime Minister Giorgia Meloni, closer to Trump than some other EU leaders, described the tariff threat on Sunday as "a mistake" and told a briefing during a trip to Korea that she had spoken to Trump a few hours earlier and told him what she thought.
She planned to call other European leaders later on Sunday. Italy has not sent troops to Greenland.
Asked on Sunday about how Britain would respond to new tariffs, Culture Secretary Lisa Nandy said allies needed to work with the United States to resolve the dispute.
"Our position on Greenland is non-negotiable ... It is in our collective interest to work together and not to start a war of words," she told Sky News.
The tariff threats do though call into question trade deals the United States struck with Britain in May and the European Union in July.
The limited agreements have already faced criticism about their lopsided nature, with the United States maintaining broad tariffs, while their partners are required to remove import duties.
The European Parliament looks likely now to suspend its work on the EU-US trade deal struck in July. The assembly had been due to vote on removing many EU import duties on January 26-27, but Manfred Weber, head of the European People's Party, the largest group in parliament, said in a post on X late on Saturday that approval was not possible for now.
Trump's threat came just as the European Union was signing its largest ever free trade agreement, with South American bloc Mercosur, in Paraguay. Von der Leyen said that the agreement sent a very strong signal to the rest of the world.
"We choose fair trade over tariffs. We choose a productive, long-term partnership over isolation," she said.
