Canada began a staggered loosening of pandemic restrictions on Monday as Prime Minister Justin Trudeau urged vigilance and baby steps to avoid a COVID-19 resurgence.

The Atlantic coast province of New Brunswick, after seeing no new cases in a week, was first to relax social distancing rules starting with the opening of parks and beaches.

Saskatchewan is set to allow businesses to reopen next week.

And Ontario and Quebec, which recorded the most coronavirus cases, largely at nursing homes, were to unveil their respective schedules this week for the reopening of their economies.

"Different provinces and territories will be able to move at a different pace," Trudeau told a daily briefing.

He stressed the need for a gradual and coordinated approach "to make sure we do this very carefully, based on absolutely the best scientific advice."

"If we get this wrong, everything we have done, everything we have sacrificed over the past many weeks, could have been in vain," he warned.

Federal guidelines for reopening of businesses include ramping up testing for the coronavirus and ensuring there is sufficient healthcare capacity "to handle a possible surge" in cases.

Each province, however, is responsible for setting its own conditions for lifting restrictions.

Trudeau said he has "tremendous confidence" in each province's plan.

However, he said Canadians should brace for a resurgence of cases in the fall and not expect a return "to normal" anytime soon.

"Historians remember from the 1918 Spanish Flu epidemic that the spring was pretty bad," Trudeau said. "But the fall was much worse."

Canadians need to "stay vigilant, every step of the way" until there is an effective treatment or vaccine, he said.

The coming months, Trudeau said, will see a "careful reopening in certain sectors of the economy and certain things being allowed as people try to get back to something a little more like normal."

"Normal is something that is a long way off for all of us," he added. "And if we want life to get back to the way it was exactly before, it won't."

As of Monday, there were 48,229 coronavirus cases in Canada, including 2,781 deaths.