Former US President Barack Obama takes a sharp swipe at Donald Trump over his approach to Canada, trade wars and international relations during a rally in Detroit, Michigan. Obama sarcastically refers to Canada as America's supposed “historical adversary” before describing Canadians as “the nicest people.” He criticizes Trump's rhetoric about annexing Canada and making it the 51st US state, arguing that repeated threats and hostile remarks have angered America's neighbour. Obama's comments put the spotlight on US-Canada relations, Trump's trade policies and the growing political debate over America's foreign policy and diplomatic priorities.