OTTAWA—Mark Carney took over Friday as Canada’s prime minister, planting a former central banker known for navigating crises in the middle of a trade war with President Trump and likely kicking off a national election.

Mark Carney has been sworn in as Canada’s prime minister, after Justin Trudeau formally stepped down, as the country faces questions about its sovereignty from Donald Trump and a trade war with Canada’s largest trading partner,

By Promit Mukherjee and David Ljunggren OTTAWA (Reuters) -Ex-central banker Mark Carney was formally sworn in as prime minister of Canada on Friday, putting him in a position to fight tariffs from U.S.