Addressing the European Parliament, von der Leyen said Europe had to toughen up to influence the world around it -- while warning the United States that strife between "allies" over Greenland would only embolden rivals of the West.

"The shift in the international order is not only seismic, but it is permanent," she told lawmakers, citing the "volatile situation" around Greenland, but also Russia's relentless bombing of Ukraine and tensions from the Middle East to the Indo-Pacific.

"We will need a departure from Europe's traditional caution," said the European Commission President.

"We now live in a world defined by raw power -- whether economic or military, technological or geopolitical. And while many of us may not like it, we must deal with the world as it is now."

Speaking as US President Donald Trump was on his way to the annual meeting of the World Economic Forum in the Swiss ski resort of Davos, von der Leyen described his threat to slap tariffs on European allies as "simply wrong".

"If we are now plunging into a dangerous downward spiral between allies, this would only embolden the very adversaries we are both so committed to keeping out of the strategic landscape," she said.

"We are at a crossroads," von der Leyen told lawmakers, as EU leaders prepare to meet Thursday in Brussels to forge a common response to Trump's threats.

"Europe prefers dialogue and solutions -- but we are fully prepared to act, if necessary, with unity, urgency and determination," she said.

Trump insists that mineral-rich Greenland is vital for US and NATO security against Russia and China, as a melting Arctic opens up and the superpowers jostle for strategic advancement.

But his push to acquire it from Denmark has enraged European leaders, plunging US-EU relations to an historic low.