Prime Minister Justin Trudeau said today he expects new restrictions on non-essential travel at the Canada-U.S. border to take effect Friday night, but cautioned that both sides are still fine-tuning the agreement.

On Wednesday, Trudeau and U.S. President Donald Trump agreed to stop travellers from crossing the border for recreational and tourism purposes as the two nations work to slow the spread of the novel coronavirus.

"We are continuing to work on the fine-tuning of the agreement between Canada and the U.S. I think it's almost there," Trudeau told reporters Thursday during the latest of his now-daily briefings from Rideau Cottage, where he works from self-isolation.

"My understanding is the measures will probably come into place on the night between Friday and Saturday, so in about a day and a half."

Both countries have insisted that trade and key supplies will continue to flow across the border and people who need to cross for essential work will still be able to do so.

Canadian citizens and permanent residents will still be able to get home, although the government says travellers presenting symptoms won't be able to board flights.

Public Safety Minister Bill Blair said international students, workers on visas and temporary foreign workers will also be able to enter Canada, with the expectation that they'll respect the government's request to self-isolate for 14 days.

Deputy Prime Minister Chrystia Freeland says all asylum seekers crossing into Canada at Roxham Road in Quebec will be temporarily housed and quarantined for 14 days.