(Recasts, adds detail on wait times, migrants)
By David Ljunggren and Jeff Lewis
OTTAWA/TORONTO, March 20 (Reuters) - Canada will turn back irregular migrants walking over the U.S.-Canada border, Prime Minister Justin Trudeau said on Friday, as a lockdown on non-essential travel across the world's longest undefended border was set to come into effect.
Canada, which closed its borders to most foreign nationals, agreed with the United States this week to close their shared border. A notice from the U.S. Homeland Security Department (DHS) said restrictions will begin at 11:59 p.m. EDT Friday and last until April 20.
Canada has 925 cases of the COVID-19 respiratory illness caused by the coronavirus, and 12 deaths.
Trudeau said the measure to return asylum seekers was a temporary one to protect the health of Canadians during the coronavirus outbreak.
"The people who crossed up until today will be in isolation ... but in future those trying to cross will be turned back to U.S. authorities," said Trudeau, speaking outside his house where he has been in isolation since his wife tested positive for the virus.
Thousands have illegally crossed the Canada-U.S. border to file refugee claims in recent years, spurred by tougher U.S. immigration policies under President Donald Trump’s administration.
As the border deadline approached, traffic was already snarled on some crossings early on Friday.
"There's headlights as far as I can see," said Mayor Jim Willett in the tiny border village of Coutts, Alberta. "It’s been, for the last few days, more or less a steady stream of traffic from the south."
The Canada Border Service Agency attributed delays to stepped-up screening measures.
Canadian Foreign Minister Francois-Philippe Champagne, 49 who went into self-isolation on Thursday, said his test results for COVID-19 came back negative on Friday.
Earlier on Friday, miner New Gold Inc suspended operations at an Ontario mine after a significant number of workers making cross-border trips to the United States went into self-isolation.
New Gold's Rainy River mine is located about 65 kilometres north of Fort Frances, Ontario, which straddles the U.S. border. About 70% of the workforce is composed of local residents who make frequent short trips into Minnesota, the company said.
Canada on Friday said it would support businesses to rapidly scale up production and re-tool manufacturing lines to develop critical health and safety equipment.
Ottawa plans to provide C$27 billion ($18.6 billion) in direct support to families and businesses struggling because of the coronavirus outbreak.
That is expected to blow out the fiscal deficit and lead to higher government borrowing by nearly 40%, according to Reuters calculations. (Reporting by Arundhati Sarkar in Bengaluru and Jeff Lewis in Toronto; editing by Shounak Dasgupta, Jason Neely and Andrea Ricci)