President Donald Trump lashed out at US allies on Monday in a Twitter rant focusing on trade following a contentious G7 summit of economic powers in Canada at the weekend.

"Fair Trade is now to be called Fool Trade if it is not Reciprocal," Trump tweeted, as he criticised Canadian tariffs on imports of US milk. Canadian Prime Minister Justin Trudeau then "acts hurt when called out!" Trump wrote. Trump pulled out of endorsing a joint communique after the G7 meet finished on Saturday with the US president accusing Trudeau, the summit's chairman, of dishonesty.