Canadian Prime Minister Justin Trudeau has said he expects Canada and the US to be in a trade war for the foreseeable future after having what he called a colourful but constructive call with US President Donald Trump this week.

Mr Trudeau said the two sides discussed tariffs, and that they are “actively engaged in ongoing conversations in trying to make sure these tariffs don’t overly harm” certain sectors and workers.

He also reiterated that “we will not be backing down from our response tariffs until such a time as the unjustified American tariffs on Canadian goods are lifted”.

Donald Trump put 25% taxes, or tariffs, on Mexican and Canadian imports, though he limited the levy to 10% on Canadian energy (Win McNamee/Pool Photo via AP)

Mr Trump launched a new trade war on Tuesday by imposing tariffs against Washington’s three biggest trading partners, drawing immediate retaliation from Mexico, Canada and China and sending financial markets into a tailspin.

Mr Trump put 25% taxes, or tariffs, on Mexican and Canadian imports, though he limited the levy to 10% on Canadian energy.

A day after the new tariffs took effect, Mr Trump said he would grant a one-month exemption for US carmakers.

The announcement came after Mr Trump spoke on Wednesday with leaders of Ford, General Motors and Stellantis, the parent company of Chrysler and Jeep.

His press secretary said Mr Trump told the chief executives to move car production to the US to avoid tariffs.