US Trade Representative Jamieson Greer, meanwhile, warned Canada's boycott of US alcohol over tariffs might require "enforcement action".

Washington is reportedly seeking concessions before agreeing to open negotiations on revising the US trade pact with Canada and Mexico.

US Trade Representative Jamieson Greer, meanwhile, warned Canada's boycott of US alcohol over tariffs might require "enforcement action".

The prime minister's comments come after a US trade official said the US might have to take action over a provincial boycott of American wine and spirits.