Donald Trump has called Justin Trudeau "two-faced", cancelled a scheduled press conference and left the NATO summit early.
Mr Trump's comment followed a hot mic picking up Justin Trudeau, Emmanuel Macron and Boris Johnson making jokes at the US president's expense at Buckingham Palace last night.
It's been a day of drama, personal tensions and deep ideological division within NATO.
RNZ's correspondent in London is Vincent McAviney.
