VANCOUVER -- Mayors across Canada are calling for federal leadership on the "national emergency" of overdoses by ensuring provinces provide timely access to addiction treatment and by launching public education campaigns.

Vancouver Mayor Gregor Robertson, who heads a task force of the big city mayors caucus on the opioid crisis, said he and his counterparts in 12 other cities agree the situation is so dire that Ottawa must take a leadership role if jurisdictions are not moving fast enough to save lives.

Federal Health Minister Jane Philpott said last month she's frustrated with provinces and territories that have not provided her with information on overdose deaths despite repeated requests.

"We are in a national public health crisis in Canada," Philpott's press secretary, Andrew MacKendrick, said in a statement Thursday on behalf of the minister, who was unavailable. "Minister Philpott is committed to using every lever at her disposal to combat this crisis, and to working with all levels of government and partners across the country to do so."

Robertson said some provinces are "dragging their feet" on data collection but the federal government must step in with a standardized format to gather the information, which should be reported publicly at least every quarter.

"It's shocking when this epidemic is sweeping across Canada, when facts are being withheld," Robertson said in an interview, noting Vancouver collects weekly information on the number of fatal and non-fatal overdoses while the provincial coroner's service publishes monthly updates on its website.

The service said there were 347 drug overdose fatalities in British Columbia between January and March, putting the total on track to surpass the record 931 illicit drug deaths last year, many involving the painkiller fentanyl.

"It's a human catastrophe and it's taking an enormous toll on first responders and we can't withstand this pace for much longer," Robertson said, adding a co-ordinated response involving all levels of government is also essential to ensure that federal funds are directed toward removing barriers to treatment.

MacKendrick said the Public Health Agency says it has been working with the provinces and territories to develop a common reporting template to be submitted on a quarterly basis.

Across Canada, about 2,000 people died from opioid overdoses in 2015, the Centre for Addiction and Mental Health has said, adding the number is headed even higher this year.

Robertson and his counterparts on the task force, which is part of the Federation of Canadian Municipalities, say addiction treatment is essential, including medically supervised opioid substitution therapy and prescription heroin for people who haven't responded to other forms of intervention.

The Vancouver Police Department issued its own report Wednesday calling for treatment on demand, saying the opioid crisis is taxing officers who can't immediately refer people who need help and that reviving them with the overdose-reversing drug naloxone isn't good enough.

"There's no question this is a national emergency," Robertson said, adding the mayors debated whether the federal government should invoke the National Emergency Act.

"It's arguable whether that would make a difference. What's essential here is that provinces immediately support treatment on demand that's necessary to save lives."

The high number of overdose deaths in B.C. prompted the provincial government to open 23 overdose prevention sites so people could inject illicit drugs while monitored by trained staff.

Robertson said giving people a place to use drugs under supervision is one of the first lines of defence to reduce overdose deaths but most provinces aren't providing that service.

The mayors said preventing deaths will require all four pillars of the Canadian Drugs and Substances Strategy, including harm reduction, treatment, prevention and enforcement, which includes national protocols for the handling of potentially deadly fentanyl and the even more lethal drug carfentanil.

Vancouver has been at the forefront of drug policy, first by opening North America's only supervised-injection clinic in 2003, and later by providing the only injectable heroin program on the continent, though it has a long wait list.