Ontario, Canada's most populous province with 14 million people, has for several days been battling record coronavirus cases

Canada will funnel additional health staff and equipment into virus-hit Ontario as the province battles a worrying spike in COVID-19 infections, Prime Minister Justin Trudeau said Sunday.

The government will mobilize from different federal departments and deploy them to Ontario, particularly the Toronto region, where "the situation is most critical," Trudeau said in a video posted on Twitter.

Ontario, Canada's most populous province with 14 million people, has for several days struggled with record coronavirus cases, hospitalizations and intensive care patients, all of which are threatening to overwhelm its system.

On Sunday, the province reported 4,250 new cases, 18 new deaths and 2,107 new hospitalizations.

The government is in discussion with multiple provinces, including Nova Scotia and Newfoundland, to free up personnel, equipment and resources "over the coming days," the prime minister said.

Ottawa will cover the transport costs and coordinate the transfer of caregivers to Ontario, he said.

The will also send rapid COVID-19 tests to the areas of Ontario that have been the most affected by the pandemic.

"Canadians are watching surging cases, driven by more contagious variants in places across the country, including in our largest province and Canada's largest city," Trudeau said in his video message.

"Things will get better. And until they do Ontario, Canadians, we have your back. Together, we will get through this," Trudeau added on Sunday.

On Friday, Ontario announced it was tightening its lockdown orders to curb the pandemic, including closing its inter-provincial borders to non-essential travel.

Ontario Premier Doug Ford lengthened the lockdown now in effect by two weeks until May 19, and ordered Ontario residents to go out only for their .

The provincial government is also limiting capacity at essential businesses, such as pharmacies or supermarkets, as well as at weddings, funerals and religious ceremonies.

After a slow start, Canada's vaccination campaign has picked up. Nearly 24 percent of the population has received at least one vaccine dose, according to the site COVID-19 Tracker Canada.

To widen access, the minimum age to receive the AstraZeneca vaccine will be lowered from 55 to 40 in Ontario, a spokesperson for the province's told AFP Sunday.

The National Advisory Committee on Immunization (NACI) had recommended at the end of March to suspend use of the AstraZeneca vaccine in people under 55 to evaluate the risk of blood clots.

But Health Canada said Wednesday that its analysis indicates there is no need to restrict the jab's use. NACI is reviewing its position, Health Canada said.

Canada has recorded more than 1.1 million cases since the start of the pandemic and about 23,600 deaths.