The GM logo is seen at the General Motors Lansing Grand River Assembly Plant in Lansing, Michigan October 26, 2015.
The GM logo is seen at the General Motors Lansing Grand River Assembly Plant in Lansing, Michigan October 26, 2015. Reuters / Rebecca Cook

General Motors Co and Chrysler-parent Stellantis said on Thursday they were forced to cancel or scale back some shifts because of parts shortages stemming from Canadian trucking protests against pandemic measures.

Stellantis plants said all of its North American plants are running as of Thursday morning, "but a number of U.S. and Canadian plants cut short second shifts Wednesday night due to parts shortages caused by the closure of the Detroit/Windsor bridge."

GM said was forced to cancel two production shifts at a plant in Michigan where it builds sport utility vehicles after Canadian trucking protests.

The largest U.S. automaker said it had canceled a shift on Wednesday and a shift Thursday at its Lansing Delta Township plant. Both Ford Motor Co and Toyota Motor Corp said on Wednesday they had been forced to halt some operations because of supply chain disruptions stemming from protests that have snarled traffic at the Ambassador Bridge connecting Detroit and Windsor, Ontario.

Stellantis said the "situation at the Ambassador Bridge, combined with an already fragile supply chain, will bring further hardship to people and industries still struggling to recover from the COVID-19 pandemic. We hope a resolution can be reached soon so our plants and our employees can return to normal operations."

The White House said Wednesday it was talking to automakers, Canada and customs officials to try avoid disruptions to auto production.