Retailers predict prices ‘highly likely’ to rise almost immediately after 25% duty came into effect on exports from Mexico

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Americans have been warned to brace for higher prices within days after Donald Trump pulled the trigger on Monday and imposed US tariffs on goods from Canada and Mexico, and hiked tariffs on China.

Global stock markets came under pressure again on Tuesday, with leading indices falling sharply – and the benchmark S&P 500 losing all its post-election gains – as Canada, Mexico and China vowed to retaliate, and investors balked at the prospect of an acrimonious trade war.