Donald Trump’s sudden shift on Ukraine has shaken the transatlantic alliance, prompting European leaders to travel to Washington in a bid to restore the relationship.

French President Emmanuel Macron and British Prime Minister Keir Starmer will meet with Trump separately at the White House this week to urge him to maintain support for Kyiv.

Fears are growing in European capitals that the post-World War II bond with the U.S. could be at risk as Trump seeks talks with Russian President Vladimir Putin.

Many see Trump as abandoning the traditional U.S. commitment to a rules-based world order in favor of a nationalist approach that aligns with Moscow and Beijing, causing alarm across Europe, which has relied on U.S. security guarantees for 80 years.

"The Europeans are running around with their hair on fire," said Max Bergmann, director of the Europe, Russia, and Eurasia program at the Center for Strategic and International Studies.

'Other side of the ocean'

For his part, Trump insists that he is just seeking peace in Ukraine.

"I think that President Putin and President Zelensky are going to have to get together. Because you know what? We want to stop killing millions of people," Trump told reporters in the Oval Office on Friday.

But Trump's embrace of Kremlin talking points on Ukraine -- calling President Volodymyr Zelensky a "dictator without elections" and blaming Ukraine for Russia's 2022 invasion -- has caused alarm in Europe.

It has also reinforced suspicions that Trump is effectively pulling the plug on decades of US support for Europe. In Trump's view, European officials fear, the United States, Russia and China will instead look after their own spheres of influence closer to home.

"You know, it doesn't affect the United States very much. It's on the other side of the ocean," Trump added on Friday about the Ukraine war.

Even in his first term he threatened to pull out of the NATO military alliance and questioned why the United States spends huge amounts on keeping troops in Europe.

Trump's meetings with Macron on Monday and Starmer on Thursday could therefore be testy. 

Macron said he would tell Trump not to be "weak" on Ukraine. Britain and France have both offered to send peacekeepers in the event of a deal to end the war, but Starmer has pushed for a US "backstop".

Trump for his part accused both leaders of doing "nothing" to end the Ukraine war over the past three years.

'Dangerous moment'

Many Europeans are also realizing that the writing could be on the wall.

"We experience now quite a difficult and very dangerous moment when both parts of the transatlantic community, so to say, are getting more and more away from each other," former Polish prime minister Mateusz Morawiecki told AFP at the Conservative Political Action Conference (CPAC) near Washington.

For Nigel Gould-Davies, Senior Fellow for Russia and Eurasia at the London-based International Institute for Strategic Studies, it was an "unprecedented transatlantic crisis." 

"By negotiating with Russia over European heads and intervening in European politics, the United States is not only decoupling from, but deciding for and disrupting Europe," he said in a commentary.

The question now is whether Europe -- after years of talking about how they need to take more responsibility for their security umbrella in case of a rainy day -- will do so now that day has come.

Danish Foreign Minister Lars Lokke Rasmussen told AFP on Wednesday that Europe "has to do much more in order to defend ourselves, but also in order to support Ukraine. Because we are in a very, very critical period in world history."

The European Union's top diplomat Kaja Kallas on Tuesday separately urged the United States not to walk into "traps" set by Russia as it attempts to divide the West.

But for analyst Bergmann, it could also be a wake-up call for Europe.

"I think what is being asked of Europe now is not just to simply do a bit more -- but is for Europe to effectively take actions that would make it emerge, frankly, as a superpower," he said.