Alberta Premier Jason Kenney said he’s working with U.S. governors to lobby President Joe Biden and Canadian Prime Minister Justin Trudeau for an end to trucker vaccine mandates that are disrupting shipments across the border.

The top politician in Canada’s largest oil-producing province said the group is preparing a letter to Biden and Trudeau “urging them to use common sense, and end the policy that has taken thousands of trucks off the road,” according to a post on Twitter showing empty shelves at grocery stores. “This is turning into a crisis. It requires immediate action by the Canadian and U.S. governments.”

Kenney didn’t say who the governors are. An email and a phone call to Kenney’s office weren’t immediately answered.

Mexico is also concerned about the impact the mandates could have on the economy and has been discussing the topic with the U.S. government, said a Mexican foreign ministry official, who asked not to be named because the information isn’t public.

The vaccination mandates have caused chaos for Canada’s fruit and vegetable markets and threaten to trigger similar headaches in the U.S. at a time when supply chains are already struggling with labor shortages and higher costs. The disruptions risk making food more expensive and scarce, adding to inflation worries that have stressed consumers and policy makers. 

Only about half of U.S. truckers are vaccinated, according to estimates from the American Trucking Associations. While closer to 85 per cent of Canadian truckers have received the shot, industry groups say the rules will still remove as many as 16,000 drivers off the road.

Drivers reported wait times between three to four hours at the U.S.-Canada border crossings in Detroit this past weekend, according to Brad Hitchcock, the owner of a Michigan-based trucking firm. The wait time used to be roughly 15 minutes, he said.

The cost of trucking is also surging. 

U.S.-Canada trucking rates, already elevated amid a tangle of pandemic-related disruptions and driver shortages, began climbing last week just days after Canada’s vaccine rule took hold, according to David Spickler, president and majority owner of Bismarck, North Dakota-based Lighthouse Commodities, an exporter of corn and other farm products into the U.S.’s northern neighbor.

“You’ve got a trucking shortage to begin with, further exacerbated by the COVID supply-chain disruptions, and now you’ve put in this arbitrary vaccine mandate,” he said in an interview Friday.

Cross-border rates that had already doubled in some cases before the mandate spiked to as much as 150 per cent higher, Spickler said. 

Most grains and fertilizer shipped between America’s upper Midwest and the Canadian prairies travel by truck, according to Spickler.

U.S. farmers in the region are nervous that if the trucking disruptions continue it could hinder the spring wheat planting season set to begin in a couple months. It also threatens to worsen the recent bout of surging inflation for key farming products like fertilizer, a lot of which comes from Canada.

Along with fertilizer, corn, soy meal and livestock, the transit slowdown is threatening specialty grains in Canada, including barley and peas, that typically are shipped to the northern U.S. for processing.