The U.S. said it disapproves of any creative accounting by European allies to reach a new NATO spending target, putting Italy on the spot as the government weighs whether to count the construction of the world’s longest suspension bridge as military expenditure.

Along with other members of the North Atlantic Treaty Organization, Italy committed to raising defense spending to 5% of GDP, satisfying a demand by President Donald Trump, at a June summit in The Hague. The pledge prompted questions over whether a debt-saddled and stagnant economy can pull it off. It also drew scrutiny to an idea that a $15.7 billion project connecting the island of Sicily to Italy’s mainland could be paid for by classifying it as defense-related.

Not so fast, the U.S. warns.

“I have had conversations even today with some countries that are taking a very expanded view of defense related spending,” U.S. Ambassador to NATO Matthew Whitaker said in an interview at the Bled Strategic Forum in Slovenia on Tuesday.

It was “very important” that the 5% target referred specifically to defense and defense-related spending and that the commitment was taken “with a straight face,” according to the envoy.

“It wasn’t bridges that have no military strategic value,” he said. “It was not schools that somehow, in some imaginary fantasy land, would be used for some other military reason.”

Asked specifically whether the bridge over the Strait of Messina falls into the category of legitimate military spending, Whitaker was clear.

“I have been watching that situation very carefully,” he said. “The nice thing about this time at NATO as compared to the Wales summit in 2014 is we have mechanisms for monitoring.”

A number of Italian officials and politicians have been mulling the possibility of classifying the bridge as a military asset that could therefore be counted within the NATO expenditure.

One argument was that Sicily hosts a number of key military bases, including ones used by NATO forces. A government document in April described the bridge as being of “strategic importance” for “national and international security” and said that “it will play a key role in a context of defense and security, facilitating the movement of Italian and allied armed forces.”

There’s no firm decision yet and the idea has been batted around at a ministerial level, between the Treasury, the Defense Ministry and the body responsible for infrastructure.

Italian Deputy Prime Minister Matteo Salvini, who also oversees transport and has spearheaded the bridge effort, has kept options open. “It could be a dual use, so that there could be a multiple use also for security reasons,” he told reporters at a news conference last month.

But the U.S. is looking for evidence its allies are spending on battalions, artillery and tanks - items necessary for a fight - and not on extravagant feats of engineering. Building a bridge to Sicily has been a dream since the time of Italian dictator Benito Mussolini and was revived, only to be abandoned, by the late former Prime Minister Silvio Berlusconi.

Whitaker’s assessment is that while Europe has stepped up military spending, it’s not fast enough. As he tours the region reassuring allies that the U.S. is “not going anywhere” in relation to its commitment to NATO, he’s delivering three messages.

Lack of troops: “I’m concerned that there’s just not enough war fighters in Europe that are European countries.”

Weak growth: “I think Europe really needs to spend some time on fixing their economic engine instead of trying to just protect their industries.”

Cyber risks: “I really believe if there’s another land war in Europe that the first shot fired will be a cyber attack or some other type of hybrid act.”

Those last observations are significant, coming a day after a plane carrying European Commission President Ursula von der Leyen was disrupted by jamming as it landed in Bulgaria. Authorities said the interference was likely initiated by Russia.

With assistance from Andrea Dudik, Jan Bratanic and Donato Paolo Mancini.

previous coverage

• Italy’s proposed Sicily bridge could double as military asset

related stories

• NATO defense spending surges to record $1.6 trillion as higher target looms