STORY: To stop vehicles bearing migrants from barreling across the Canadian border into the United States, blocks like these have been installed on rural roads that intersect the border.But Royal Canadian Mounted Police Sergeant Daniel Dubois explains they aren't a fail safe solution.

Canadian premiers have gathered to discuss ways to respond to U.S. president-elect Donald Trump’s threat to impose a 25 per cent tariff on Canadian goods, but they have struggled to agree on what actions to take.