With leaders expected to agree to a deal ramping up defence spending designed to keep Trump happy, the alliance wants to present a message of unity and strength.

Here's how NATO is hoping to avoid any temper tantrums from Trump that could spoil the party:

- Keep it short -

With just a dinner hosted by the Dutch king on Tuesday and one two-and-a-half-hour session involving NATO's 32 leaders on Wednesday, the summit is a short one.

Cutting it down to the bare bones is fully intentional and modelled around the last gathering of NATO leaders Trump attended in London in 2019.

"Meetings are being kept short, contentious subjects avoided," said Jamie Shea, a former NATO official involved in planning previous summits.

"They're making sure Trump isn't bored with lengthy meetings where he has to stay for hours after he's made his own speech."

- Focus on good news -

It's not only the meeting that will be short -- but also the summit's final declaration.

In total it should be just five paragraphs long, or one page, much shorter than the voluminous statements of years gone by.

Featuring prominently will be the new spending deal that allows Trump to claim a major foreign policy victory.

Cracks between Washington and Europe on how to deal with Russia and Ukraine will be largely papered over thanks to some diplomatic finessing.

Both will only be mentioned in passing and the focus will be on the subject Trump cares most about: money.

- Zelensky sidelined -

One of the biggest headaches for NATO was what to do about Ukraine's President Volodymyr Zelensky.

The war-time leader has been a central figure at recent summits and European allies were desperate to keep sending a signal of strong support.

But given Trump's animus towards Zelensky after their infamous Oval Office bust-up, there was little appetite to have them spend too much time together.

In the end NATO decided to sideline the Ukrainian leader by inviting him to the dinner with the king and an industry forum -- but not to the main work session with the alliance's members.

- But expect the unexpected -

But however well NATO's planners do their job, there is no way to fully mitigate the chances that an outburst from Trump could derail the event.

At his first NATO summit in 2018, Trump publicly berated Germany, had a frosty exchange with then NATO boss Jens Stoltenberg and even physically shoved Montenegro's leader aside.

And last time around, in Britain in 2019, the NATO summit was overshadowed by Canada's Justin Trudeau being caught gossiping about Trump on hot mic.

With the Iran-Israel conflict entering dangerous new territory following US strikes on Tehran's nuclear sites, and a trade stand-off still pitting Washington against Europe, there are plenty of topics beyond NATO that could cast a long shadow.