Nato leaders are meeting in The Hague to decide on ramping up defence spending to 5% of their countries’ economic output, following months of pressure from US President Donald Trump.

“For too long, one ally, the United States, carried too much of the burden,” Secretary General Mark Rutte said in opening remarks in which he praised Trump for his leadership. “That changes today.”

The Hague summit has been described by several leaders as historic, and Rutte said decisions made on Wednesday would include continued support for Ukraine while pushing for peace.

Only Spain has rejected the target of spending 3.5% on defence by 2035, with a further 1.5% on related projects.

The US president said on Wednesday it was a “great victory for everybody, I think. We will be equalised shortly, and that’s the way it has to be”.

Spanish Economy Minister Carlos Cuerpo appeared to double down on his government’s of the 5% target, saying Madrid was making an “enormous effort” to reach a target of 2.1%. “The discussion about the percentage is misguided,” he told Spanish radio.

The Belgian government had also expressed reservations, but Prime Minister Bart de Wever told reporters that while it wouldn’t be easy “3.5% within 10 years is a realistic goal”.

The Hague summit, which began with a dinner on Tuesday night hosted by King Willem-Alexander and Queen Maxima, has been scaled back so Wednesday’s set-piece gathering of leaders was due to last only two and a half hours, with a short communique agreed at the end.

Rutte told Nato leaders that they were meeting at a “dangerous moment”, and that the defence alliance’s guarantee of mutual defence – “an attack on one is an attack on all, sends a powerful message”.

As the leaders gathered for the traditional “family photo”, Spanish Prime Minister Pedro Sánchez appeared to stand by himself at the far end of the group.

Slovakia has also raised concerns about the big hike in defence spending, but President Peter Pellegrini has indicated that Bratislava will not stand in the way.

Trump’s visit to The Hague was his first trip to a Nato summit since 2019 and he was due to meet Ukraine’s Volodymyr Zelensky on the sidelines afterwards.

However, the US president was more keen to talk about conflict in the Middle East than the war in Ukraine, when he spoke to reporters on Wednesday.

“He’s got a little difficulty, Zelensky, a nice guy,” said Trump. “I’ve spoken to Putin a lot… he volunteered help on Iran. I said do me a favour, help us on Russia, not Iran.”

The US president had earlier appeared to raise questions about the alliance’s mutual defence guarantee, known as Article Five.

“There’s numerous definitions of Article Five, you know that right?” he told reporters on Air Force One on Tuesday.

Mark Rutte later sought to quash concerns about Trump’s comments, insisting that his European colleagues should stop worrying about the US commitment to the Western alliance and focus on investing in defence and supporting Ukraine.

UK Prime Minister Sir Keir Starmer said Nato was as relevant and important now as it had ever been: “We live in a very volatile world and today is about the unity of Nato, showing that strength. We’re bigger than we were before, we’re stronger than we were before.”