After departing from the Quebec summit for Singapore, Trump tweeted that Trudeau’s remarks at a news conference, where he said Canada would not be pushed around, “were very dishonest and weak”.
He said that other countries were imposing “massive tariffs” on the US.
Trump had earlier signed the joint statement agreed by all the G7 nations despite the trade row. The joint communique, advocating a “rules-based trading system”, was reached despite tension over US tariffs on steel and aluminium imports.
Canadian Prime Minister Justin Trudeau vowed afterwards to press ahead with retaliatory tariffs on 1 July.