NATO leaders gather in The Hague on Wednesday for a summit tailor-made for U.S. President Donald Trump, with European allies hoping a pledge to hike defence spending will prompt him to dispel doubts about his commitment to the alliance.

Spain reached a deal with NATO to be excluded from a 5% of GDP defense spending target, days before the military alliance's leaders will gather at a summit, Prime Minister Pedro Sánchez said on Sunday.

As Nato leaders meet to agree big increases in targets for defence spending, some of them haven't yet met the existing ones.