Trump lashes out at Nato, alliance chief says US president 'clearly disappointed'

US President Donald Trump has slammed Nato for its absence shortly after holding a closed-door meeting with the alliance's Secretary General Mark Rutte.

"NATO WASN’T THERE WHEN WE NEEDED THEM, AND THEY WON’T BE THERE IF WE NEED THEM AGAIN. REMEMBER GREENLAND, THAT BIG, POORLY RUN, PIECE OF ICE!!! President DJT," Trump said in a post on Truth Social. 

Speaking to CNN, Rutte said their talk in Washington was "very frank" and "open".

"Let me be absolutely clear. He is clearly disappointed, and with many NATO allies. And I can see his point," the Nato chief said.

"But at the same time, I was also able to point to the fact that the large majority of European nations has been helpful, with basing, with logistics, with overflights, with making sure that they live up to the commitments, and there’s also widespread support for the fact that’s degrading the nuclear and the ballistic missile capacity for Iran was really crucial. And that only the US was able, at this point, to do that."