The G7 summit ended in farce and a renewed threat of global trade war yesterday as US President Donald Trump abruptly rejected the text of a consensus statement and bitterly insulted the Canadian host.

Just minutes after a joint communique that had been approved by the leaders of the Group of Seven allies was published in Canada's summit host city Quebec, Trump launched a Twitter broadside from aboard Air Force One. The US leader had left the meeting early en route for Singapore and a historic nuclear summit with North Korea's Kim Jong Un, only to take exception to comments made by Canada's Prime Minister Justin Trudeau at a news conference back on the ground.