A line of trucks are seen on Highway 400 as truckers make their way to Ottawa during the "freedom convoy" protest in Vaughan, Ontario, Canada, on Jan. 27, 2022. The "freedom convoy" was sparked by outrage over a vaccine mandate recently imposed on Canadian-U.S. cross-border truckers.(Photo: Xinhua)

Ford and Toyota on Wednesday both said they were halting some production as anti-coronavirus mandate protesters blocked US-Canada border crossings that have prompted warnings from Washington and Ottawa of economic damage.

Many COVID-19 pandemic-weary Western countries will soon mark two years of restrictions as copycat protests spread to Australia, New Zealand and France now the highly infectious Omicron variant begins to ease in some places.

Horn-blaring protests have been causing gridlock in the capital Ottawa since late January and from Monday night, truckers shut inbound Canada traffic at the Ambassador Bridge, a supply route for Detroit's carmakers and agricultural products.

A number of carmakers have now been affected by the disruption near Detroit, the historic heart of the US automotive sector, but there were other factors too such as severe weather and a shortage of semi-conductor chips.

Toyota, the top US seller, said it is not expected to produce vehicles at its Ontario sites for the rest of the week, output has been halted at a Ford engine plant and Chrysler-maker Stellantis has also been disrupted. Another border crossing, in Alberta province, has been closed since Tuesday.

More than two-thirds of the C$650 billion($511 billion) in goods traded annually between Canada and the US is transported by road.

Starting as a "Freedom Convoy" occupying downtown Ottawa opposing a vaccinate-or-quarantine mandate for cross-border truckers that were mirrored by the US government, protesters have also aired grievances about a carbon tax and other legislation.

"I think it's important for everyone in Canada and the United States to understand what the impact of this blockage is - potential impact - on workers, on the supply chain, and that is where we're most focused," White House spokesperson Jen Psaki said on Wednesday.

"We're also looking to track potential disruptions to US agricultural exports from Michigan into Canada."

Ford suspended engine output in Windsor while its Oakville factory near Toronto is operating with a reduced schedule, as it warned the Ambassador Bridge closure "could have widespread impact on all automakers in the US and Canada."

Reuters