Frontrunners include Chrystia Freeland and Mark Carney, who are making the case they can guide Canada through domestic and international issues. At the top of the list: mounting trade tensions with the United States.

Canada's Liberal Party will on Sunday announce Prime Minister Justin Trudeau's successor as both party chief and head of the country's government in the midst of a trade war with the United States that could cripple the Canadian economy.

After decades of bilateral stability, the vote on Canada’s next leader now is expected to focus on who is best equipped to deal with the U.S.