The walkout at one of Canada’s biggest seaports comes as workers at more than half of U.S. ports prepare to strike.

(Reuters) -Unionized workers have begun a three-day strike at two terminals of the port of Montreal as talks over a new contract are yet to result in a labor agreement, the Canadian port's authorities said on Monday.

The union representing U.S. dockworkers signaled that 45,000 members will walk off the job at midnight, kicking off a massive strike likely to shut down ports across the East and Gulf coasts