“There is no reason why we should be so clearly militarily weaker than Russia, and therefore increasing production and intensifying our cooperation are absolutely indisputable priorities,” Tusk said in arguing for the European Union to become “a military power” in its own right.

The diplomatic push came after Trump shocked many in Europe over the weekend by appearing to invite Russia to invade any Nato member not spending enough on its own defence.

“‘You didn’t pay? You’re delinquent?’” Trump recounted telling an unidentified Nato member during his presidency. “‘No, I would not protect you. In fact, I would encourage them to do whatever the hell they want. You gotta pay. You gotta pay your bills’.”

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The Republican front-runner’s words at a campaign rally were particularly shocking for front-line Nato countries like Poland, which experienced both German and Soviet occupation during World War II and later spent decades under Soviet control. Anxieties run high there over the ongoing war just across Poland’s eastern border.

Speaking alongside Tusk in Berlin, Scholz blasted Trump’s comments.

“Nato’s promise of protection is unrestricted – ‘all for one and one for all’,” Scholz said without mentioning the former president by name. “And let me say clearly for current reasons: Any relativisation of Nato’s support guarantee is irresponsible and dangerous, and is in the interest of Russia alone.”

“No one can play, or ‘deal,’ with Europe’s security,” the chancellor added.

Earlier Monday, Scholz inaugurated a new ammunition factory, underlining Europe’s efforts to ramp up weapons production.

Tusk also urged European nations to invest more in military projects in order “to achieve as quickly as possible … in the next dozen or so months, much greater air defence capabilities, much greater production capabilities in terms of ammunition”.

Asked about Trump’s remarks, Tusk said they “should act like a cold shower for all those who continue to underestimate this increasingly real threat which Europe is facing”.

Macron, speaking alongside Tusk in Paris, said Europe’s will “to further supply and meet Ukrainian needs is crucial,” after leaders of the 27 EU member nations sealed a deal to provide Ukraine with €50 billion (US$54 billion) in support for its war-ravaged economy.

This “will enable us to make from Europe a security and defence power that is both complementary to Nato and a pillar of the Atlantic alliance, Macron said.

Trump’s call for Russia to invade Nato members ‘unhinged’, White House says

Trump’s remarks raised concerns that if reelected, he could embolden Russia to attack other countries besides Ukraine. Nato Secretary General Jens Stoltenberg issued a statement Sunday saying that Trump’s remarks put American troops and their allies at greater risk.

Nato does not require its 31 members to pay bills, but they are expected to invest a certain percentage of their own budgets – ideally, 2 per cent of their gross domestic product – on defence.

Some countries, like Poland, have long met the target. Other European nations ramped up their military spending after Russia invaded Ukraine almost two years ago.

Speaking in Rome, Italian Foreign Minister Antonio Tajani dismissed Trump’s threat as “electoral campaign joke,” but said it was legitimate for all Nato members to do their part. Italy hasn’t yet reached the 2 per cent GDP defence spending target.

“To have more influence within Nato we need a Europe with its own army,” he said. “We must look forward, because it is fair that Americans are asking us to do our part, we must have equal responsibility.”

Germany, with a post-World War II political culture of military caution, was a frequent target of Trump’s ire during his presidency for falling short of the 2 per cent target, But Berlin announced plans to step up military spending after the full-scale invasion of Ukraine and plans to hit the benchmark this year.

France’s military budget grew in recent years and reached the level of about 2 per cent of GDP.

Tusk returned to power as prime minister of his central European nation in December after eight years of rule by a national conservative government that often took an antagonistic stance with European allies, particularly Germany. As a result, Warsaw’s influence in Europe diminished.

The Weimar Triangle was created in 1991 as Poland was emerging from decades of communism as a platform for political cooperation among the three nations.

Polish Foreign Minister Radek Sikorski noted Monday that he and his French and German counterparts “meet at a dramatic, but also solemn moment”. Russian President Vladimir Putin “must not be allowed to win this war. We must fulfil our obligations toward Ukraine”.

French Foreign Minister Stéphane Séjourné said “each minute counts to get Europeans prepared to absorb the shock of a scenario that has been well described by Donald Trump.”