NATO leaders will seek to lock in US President Donald Trump's commitment to their alliance with a summit pledge to boost defence spending, as they gather Tuesday in The Hague with global attention focused on Iran.

The overriding focus of the gathering, which kicks off with dinner hosted by the Dutch king, has been on keeping Trump happy after his return to power sparked fears he could blow a hole in the seven-decade-old alliance.

Allies are keen that Trump, set to touch down in the Netherlands at 1700 GMT, will see the summit as a victory.

But there is still the chance of fireworks as Kyiv said Trump would meet Ukraine's President Volodymyr Zelensky on Wednesday, with organisers hoping the pair will avoid a repeat of their infamous Oval Office dust-up.

Central to the effort to keep Trump on board -- given his threat not to protect lower-spending NATO allies -- will be a pledge to satisfy his insistence that members cough up five percent of their GDP on defence.

To give him a headline victory, NATO's 32 countries have........

© International Business Times