Canadian Prime Minister Justin Trudeau on Monday expressed his "deep disappointment" in General Motors Co.'s decision to close its Oshawa plant, a move Canadian officials only learned about on Sunday and which led workers to walk off the job on Monday.

Canadian officials promised to aid auto workers affected by the 2019 closure, part of a wider restructuring by the automaker that will cut production of slow-selling models and slash its North American workforce.

GM said the closure affects a total of 2,973 assembly line jobs. GM's total employment in Canada is 8,150 direct jobs.