To the protesters, he said, “You can’t end a pandemic with blockades … You need to end it with science. You need to end it with public health measures.”

Earlier, White House Press Secretary Jen Psaki said US officials were “in very close contact” with Canadian border agencies about the bridge blockade.

Psaki also expressed concerns about the impacts of the protests on the US economy, saying the action “poses a risk to supply chains, to the auto industry”.

The Ambassador suspension bridge is a key trade corridor, with more than 40,000 commuters, tourists and trucks carrying US$323 million worth of goods across the span each day.

Several Canadian and American chambers of commerce and industry associations, in a joint statement, demanded the bridge be cleared, saying “as our economies emerge from the impacts of the pandemic we cannot allow any group to undermine the cross-border trade”.

Canadian anti-vax truckers inspire copycat ‘freedom’ protests

Another trade link between Coutts in the province of Alberta and Sweet Grass, Montana, has also been blocked by protesters for several days.

“This is a dramatic situation that is impacting the well-being of Canada’s relationship with the United States and impacts immensely how business is able to conduct its operations,” University of Ottawa professor Gilles LeVasseur said.

The so-called “Freedom Convoy” began last month in western Canada – launched in anger at requirements that truckers either be vaccinated, or test and isolate, when crossing the US-Canada border.

Having snowballed into an occupation of Canada’s capital, the protest has sparked solidarity rallies across the nation and abroad.

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Canada cracks down on anti-vax trucker protests, seize fuel and ban honking

Canada cracks down on anti-vax trucker protests, seize fuel and ban honking

On Wednesday Ottawa police warned protesters they could face criminal charges and their trucks could be seized if they continue their “unlawful” clogging of downtown streets.

Canadian Vehicle Manufacturers’ Association president Brian Kingston said the Ambassador Bridge blockade was “threatening fragile supply chains already under pressure due to pandemic related shortages and backlogs”.

Officials pointed to 5,000 factory workers in Windsor, Ontario being sent home early Tuesday because of the blockade, and several auto assembly plants preparing to close, as Windsor Mayor Drew Dilkens expressed fears about lasting impacts on Canadian businesses.

Michelle Krebs, a senior analyst with Autotrader in Detroit, explained that North American assembly plants rely on timely parts deliveries across the bridge.

Canada’s anti-vax truckers block key border crossing with US

The vehicle manufacturing sector “is a significant portion of the economy and an important portion of consumer spending” that has been hard hit over the past year, she said.

There were gradual improvements after October’s inventory and production disruption low point, “but this (protest) could be a setback if it lingers”.

Canada’s Public Safety Minister Marco Mendicino warned of “serious dangers for the economy” and called on protesters to “go home!”

“This is an illegal economic blockade … against all Canadians,” added Transport Minister Omar Alghabra.

Several provinces including Alberta, Quebec and Saskatchewan this week announced a gradual lifting or loosening of Covid-19 restrictions.

In Ottawa, hundreds of heavy trucks continued to block traffic and rev their engines, filling downtown with diesel fumes.

A Canadian court on Monday ordered them to stop incessant honking that upset residents and made sleep difficult.

But some protesters appeared all-too-ready to hunker down, with trucker Gavin Hodgins, parked outside Trudeau’s office, saying: “I’m not going anywhere.”