Canada on Friday will announce curbs on greenhouse gas emissions for heavy-duty vehicles like tractor trailers, the Environment Ministry said on Thursday night.
The brief announcement gave no details of what curbs might come at the Vancouver announcement, which is scheduled for 9:30 a.m. PDT (1630 GMT).
Canada, arguing it cannot afford to introduce tougher regulations than those in the United States, has traditionally acted in tandem with Washington on new rules.
Last month, Canada and the United States announced plans to boost auto fuel efficiency standards for the first time since the 1970s.
Those rules, which automakers knew for months were coming, require that cars and trucks get on average 35.5 miles per gallon (15 km per liter) by 2016, up 42 percent from current rules of just under 25 miles per gallon.
Average vehicle emissions will be limited to 250 grams of carbon dioxide per mile by 2016, down from 295 grams in 2012.