(Independent) -- Nato will reportedly put a time limit on speeches at an upcoming summit with Donald Trump, in an attempt to maintain the US President’s attention span. 

Speakers will be limited to between two and four minutes, sources within the organisation told Foreign Policy magazine. The summit of Nato’s 28 member countries will be held at the end of the month and the Belgian capital, Brussels.

“It’s kind of ridiculous how they are preparing to deal with Trump,” one source said. “It’s like they’re preparing to deal with a child — someone with a short attention span and mood who has no knowledge of Nato, no interest in in-depth policy issues, nothing. They’re freaking out.”

Mr Trump repeatedly criticised the alliance during his presidential election campaign, claiming it had outlived its usefulness and calling it “obsolete”.

His stance appeared to soften after he took office in January.

But while he has expressed support for Nato, he has repeated his view that European members are not pulling their weight in terms of defence spending.

As a result, he has repeatedly called for other member states to meet a 2014 agreement, which committed them to spending 2 per cent of their GDP within a decade.

Only the US and a handful of other countries - including the UK, Poland, Estonia and Greece - are currently meeting the target.

Despite Mr Trump’s more moderate tone, experts are concerned how he will react to the “important but painfully dull” diplomatic meetings.

“Even a brief Nato summit is way too stiff, too formal, and too policy heavy for Trump. Trump is not going to like that,” Jorge Benitez, a Nato expert with the Atlantic Council think tank, told Foreign Policy.

Another former official said: “People are scared of his unpredictability, intimidated by how he might react knowing the president might speak his mind — or tweet his mind."