US President Donald Trump has announced plans to increase tariffs on Chinese goods from 10% to 20%, and impose a 25% tariff on goods from Canada and Mexico, effective March 4 and April 2 respectively. The move is in response to China's failure to curb the flow of synthetic opioids and is aimed at encouraging domestic agricultural production. The decision has led to a drop in US stock indices and a decline in corn and soybean prices, with mirror tariffs expected from importers. Canadian Prime Minister Justin Trudeau has threatened to retaliate with a 25% tariff on US goods, while the governor of Ontario has suggested cutting off electricity to northern US states. Economists warn that the tariffs could lead to higher prices and inflation in the US.