As an update to the recently announced border restrictions, Canada's border is now essentially closed to non-essential travel.  Further details are below.

Anyone contemplating traveling to Canada from the United States or from elsewhere must review whether they may come to Canada under one of the exemptions to the travel restrictions.

Further Details from Canada

On March 26, 2020, the Government clarified its position relating to border entries.  These details were provided via two Orders in Council. One deals with entry from the United States and the other deals with entry from any other country:

March 26 Order in Council re Prohibition of Entry into Canada from the United States

March 26 Order in Council re Travel Prohibition regarding entry from all other countries (other than the USA). Foreign nationals are generally prohibited from traveling to Canada, though section 3(1) sets out exemptions to the travel ban.

In addition, IRCC updated it program delivery instruction regarding Travel restriction measures: COVID-19 program delivery (this webpage is updated from time to time).

Some Highlights

Some temporary foreign workers (work permit holders and those with work permit approvals), some international students and approved permanent residents who have not yet landed in Canada, are permitted to enter. 

The updated Program Delivery states that the following foreign nationals may travel to Canada, and now refers to new workers to be employed in "critical industries":

Temporary workers who were already established in Canada or who had made arrangements to come to Canada to work before the travel restrictions were put in place. It also includes new workers who are coming to Canada to be employed in critical industries, such as agriculture, food processing, health, transportation and emergency services.

If travelling by air, ALL travellers will need to pass a health check before being allowed to board a flight.   Anyone who shows symptoms of COVID-19 will not be allowed to enter Canada by air.  Upon arrival in Canada, a traveller's health will again be screened prior to leaving the port of entry. 

ALL travellers entering Canada must isolate themselves for a MINIMUM of 14 days, whether or not symptoms of COVID-19 are present.  This is a mandatory isolation for everyone entering Canada.

The only exception to the mandatory isolation rule are people who provide essential services and truck drivers who regularly cross the border to maintain the flow of goods.

An essential service provider seems to be determined at the discretion of the Immigration Officer at the port of entry.  Generally, an essential service provider is an individual providing a service that will allow production of an essential service to continue such as agriculture, transportation and health care.  Further clarification of an essential service has been requested and we will provide an update when available. 

Foreign nationals entering from the United States are prohibited from entering for "an optional or discretionary purpose, such as tourism, recreation or entertainment."  They also cannot enter if the have been outside Canada and the United States for more than 14 days, with some exceptions.

Conclusion

Note that further changes are likely as circumstances evolve and that we will be providing a more detailed overview.

As a practical matter, it remains to be seen how some of the provisions are interpreted and applied in the field.  It is strongly recommended that if anyone is contemplating essential cross border travel, that they first obtain legal advice from an immigration lawyer.