A poll published by the BBC ahead of the extension showed that 80 per cent of Canadians would prefer the border be shut until at least 2021.
The New York Times reports Canadian police have had a spike in calls from concerned citizens spotting vehicles with US number plates and are warning drivers that these might make them a target for vandalism.
Many Canadians fear a reopening. Canada has flattened the epidemic curve while the US has more confirmed cases and deaths from COVID-19 than any other country.
Essential cross-border workers like health care professionals, airline crews and truck drivers are still permitted to cross. Much of Canada's food supply comes from or via the US.
Americans who are returning to America and Canadians who are returning to Canada are also exempted from the border closure.
Canada sends 75% of its exports to the US and about 18% of American exports go to Canada. The U.S. Canada border is world's longest between two nations.
- With AP reporting