To win the next election, the new prime minister must quickly prove he is Canada’s best hope of managing relations with the White House.

Monday might be the last St. Patrick's Day that Mark Carney can truly claim to be Irish, as Canada's newly sworn-in prime minister moves to renounce both his Irish and U.K. citizenships.

Ex-central banker Mark Carney was sworn in as prime minister of Canada on Friday (March 14) and immediately said he could work with U.S. President Donald Trump, who is promising tariffs that could devastate the Canadian economy.