DAVOS - European leaders drew a clear line over Greenland Tuesday, vowing an "unflinching" response to Washington's threats even as US President Donald Trump said he was ready to hold a meeting in Davos about his plans to take the autonomous Danish territory.
READ: Large crowds expected for 'Hands off Greenland' protests
Leaders at the World Economic Forum (WEF) in the Swiss ski resort closed ranks against Trump's increasingly aggressive America First agenda, while Greenland's prime minister said his tiny population of 57,000 must be prepared for military force.
European Commission President Ursula von der Leyen led the European rejoinder, cautioning that Trump risked plunging US ties with the European Union into a "downward spiral".
France's Emmanuel Macron warned against US attempts to "subordinate Europe", and blasted as "unacceptable" Trump's threats to impose tariffs of up to 25 percent on countries opposed to his Greenland plans.
Trump had earlier insisted Greenland was "imperative" for security. "There can be no going back -- On that, everyone agrees!" he posted on his Truth Social platform.
The US president, who will address the annual gathering of global elites on Wednesday, has put the transatlantic alliance to the test with his demand to take over Greenland.
Europe is weighing countermeasures after he threatened levies on eight European countries, though Washington has said any retaliatory levies would be "unwise".
Von der Leyen branded the tariffs a "mistake", telling the meeting of world business and political leaders they could start a spiral that would only aid Europe's adversaries.
"So our response will be unflinching, united and proportional," she said.
- NATO at stake -
Trump has pressed on with his Greenland campaign on Truth Social, writing that he had a "very good" call with NATO secretary-general Mark Rutte in which he agreed to meet with "various parties" in Davos.
Rutte's predecessor Anders Fogh Rasmussen warned that the Republican's Greenland gambit had ignited the biggest crisis in NATO's history, and said the time for "flattering" the US leader was over.
"It is the future of NATO and the future of the world order that are at stake," he told AFP in an interview at Davos.
Greenland's Prime Minister Jens-Frederik Nielsen agreed, telling a press conference in Nuuk that while military force was "unlikely" it could not be ruled out.
"That's why we must be ready for all possibilities, but let's emphasise this: Greenland is part of NATO and, if there were to be an escalation, it would also have consequences for the rest of the world."
Trump argues he wants to protect mineral-rich Greenland from perceived Russian and Chinese threats -- although Washington already has a base there and security agreements through NATO, while analysts suggest Beijing is a small player in the region.
EU leaders will hold an emergency summit on Greenland in Brussels on Thursday.
- 'Law of the jungle' -
Other prominent foreign leaders addressing the WEF on Tuesday included Chinese Vice Premier He Lifeng, whose country has been locked in a trade war with Trump.
"A select few countries should not have privileges based on self-interest, and the world cannot revert to the law of the jungle where the strong prey on the weak," He said, without naming names.
Canadian Prime Minister Mark Carney, who has sought to reduce his country's reliance on the United States in its own tariffs feud with Trump, also voiced his support for Greenland at Davos.
Canada had benefitted from an era of "American hegemony", he said, but now had to pivot to defend the existing international order.
"Middle powers must act together, because if we're not at the table, we're on the menu," Carney said.
Other flashpoints on the WEF agenda include the crises in Venezuela, Gaza, Iran -- and Ukraine.
Europe, which is ramping up defence spending to break its security reliance on the United States, still needs Washington's help to end the Ukraine war and deter the looming Russian threat to its east.
But Ukraine's President Volodymyr Zelensky warned Tuesday that he worried the furore over Greenland could divert attention, warning of a "loss of focus during a full-scale war".
Macron, wearing sunglasses because of a broken blood vessel, sent a message to Trump to propose a G7 summit in Paris on Thursday on Greenland as well as Ukraine, with Copenhagen, Moscow and Kyiv attending on the sidelines.
But he later clarified to AFP that no such meeting was yet scheduled.
The Kremlin said Russian envoy Kirill Dmitriev plans to meet members of the US delegation in Davos -- the first to attend since Russians were excluded from the gathering following Moscow's invasion of Ukraine in 2022.
By Laurent Thomet