Heraldo de Madrid - Shaken NATO allies to meet Trump's top diplomat

President Donald Trump has rocked the foundations of Western security by casting doubt on NATO's collective defence vow, reaching out to Europe's nemesis Russia, and threatening the territory of Canada and Denmark.

In a further stoking of transatlantic tensions on Wednesday, the mercurial leader announced tariffs that will buffet allies and look set to draw retaliation.

"I know that there have been allies, for example, on this side of the pond being worried about the long-term commitment of the US to NATO," alliance head Mark Rutte said.

"But I'm absolutely convinced this alliance is there to stay with the US. Their commitment is absolutely clear."

NATO's 31 other members will be desperate to separate the trade row from their two days of talks on the alliance's future and the war in Ukraine, whose foreign minister will also attend.

Ahead of a June summit in The Hague, they're looking for details from Rubio on Trump's demands for allies to hike defence spending, warnings the United States could pull back forces from Europe, and intentions for Russia and Ukraine.

"Obviously Rubio will keep pushing us to do more," one European diplomat said, speaking on condition of anonymity.

"But we need some sort of additional reassurance from the US as well, and would be happy if he says 'we'll stand by you'."

On Ukraine, Washington has left its allies in the dark as it engages in a head-spinning rapprochement with Russia aimed at convincing President Vladimir Putin to stop his three-year war.

Nervous European countries are pleading with Trump to stand strong against Moscow as the US leader pushes for a partial ceasefire despite the warring sides trading accusations of ongoing strikes.

The president has cheered allies by menacing Putin with sanctions for dragging his feet -- but there are fears Trump ultimately may want to draw close to a country viewed as NATO's number one enemy.

Meanwhile, Britain and France are spearheading talks on sending troops to Ukraine to shore up any deal Trump may strike.

While Kyiv's future is seen as a key issue for Europe, there are also fundamental questions over the future of the NATO alliance that has underpinned Europe's security for seven decades.

Trump has long berated members for not spending enough on their own defence and is pushing them to show their commitment by massively hiking expenditure to five percent of GDP -- more than any member, including the United States, now spends.

In a bid to ratchet up pressure he has threatened to only protect those countries that cough up enough in his eyes.

NATO is looking to thrash out a new spending pledge for the Hague summit, with diplomats saying internal estimates say at least 3.5-3.7 percent of GDP needs to be spent on average to fill plans aimed at deterring Russia.

- 'Therapy session' -

Allies are scrambling to show they are doing more for their own protection as Washington warns it could look to shift assets from the continent to focus on other threats like China.

In a blistering debut at NATO in February US Defense Secretary Pete Hegseth told Europe it would now have to "take ownership of conventional security on the continent".

Diplomats and officials are calling for the United States to give them plenty of time to coordinate any drawdown so no gaps are left in Europe's defences.

So far though Washington has provided no further details on any plans to pull out its roughly 100,000 troops or the key weaponry that others would struggle to replace.

After Hegseth's shock-and-awe approach last time round, allies hope Rubio could adopt a softer tone -- albeit still insisting on Trump's priorities.

"If he doesn't say stuff to patch up our concerns then we may need a therapy session," said one NATO diplomat.

P.Sanabria--HdM