"Congratulations and thank you for your decisive action in Iran, that was truly extraordinary and something no one else dared to do. It makes us safer," Rutte wrote in a message shared by Trump on Truth Social -- and confirmed by the NATO chief's office.

Showing himself adept at borrowing the style of the US president, Rutte then turned to the meat of the NATO summit -- spending pledges -- again giving Trump the credit for bringing everyone on board.

"Europe is going to pay in a BIG way, as they should, and it will be your win," said Rutte.

"You are flying into another big success in The Hague this evening. It was not easy but we've got them all signed on to five percent," he wrote.

Keeping Trump on board within NATO by all means has been the unequivocal priority for Rutte, as the US leader stormed back to power threatening allies he would not protect them if they did not spend their fair share.

To that end, NATO leaders are set to sign up to a pledge to spend five percent of gross domestic product on defence, despite some last-minute grumbling, notably from Spain.

Piling on the praise -- while adopting Trump's habit of writing in capitals -- Rutte said this was "something NO American president in decades could get done."

And finally, playing on Trump's known love of pomp and royalty, Rutte signed off with "See you tonight at His Majesty's dinner."

Dutch King Willem-Alexander is hosting the world leaders for dinner and has invited Trump to stay over at his palace -- an invitation gratefully accepted.