The federal government says it is not interested in decriminalizing any drugs beyond marijuana, despite calls from Canada's two largest cities to consider the measure.

As the opioid epidemic washes over the country, Montreal and Toronto are urging the federal government to treat drug use as a public health issue, rather than a criminal one.

Montreal's public health department has just thrown its support behind a report released recently by Toronto's board of health which urges the federal government to decriminalize all drugs. A Health Canada report last month found that nearly 4,000 Canadians died from an apparent opioid overdose in 2017, including 303 opioid overdose-related deaths in Toronto.

In Montreal, the number of deaths relating to probable opioid overdoses was 140 for a period of a little over a year, ending June 30.

Thierry Belair, a spokesman for Health Minister Ginette Petitpas Taylor, says the federal government is not looking to decriminalize or legalize any drugs aside from cannabis.

Belair says the government understands that stigma and barriers to treatment need to be reduced, and Ottawa has taken steps in that direction.

He said the federal government has made it easier for health professionals to provide access to opioid substitution therapies; and the federal government has also approved more than 25 supervised consumption sites.

Fardous Hosseiny, national director of research and public policy at the Canadian Mental Health Association, which has advocated for decriminalization, said the organization welcomes the call from Vancouver, Toronto and now Montreal, and hopes it puts some pressure on the federal government.

"Given the scale of the opioid crisis in Canada, we know that we need to take bold action," he said.

"We know that evidence tells us that the war on drugs hasn't worked, so criminalization really stigmatizes people and creates barriers for them accessing treatment and accessing help when they need it."

Hosseiny raised Portugal's model as an example, which B.C. urged the federal government adopt. The EU country decriminalized all drugs by eliminating criminal penalties for small possession and consumption of illicit drugs in 2001.

While Prime Minister Justin Trudeau and Petitpas Taylor may not be keen to add the decriminalization of all drugs to the election banner in 2019, their party's supporters like the idea.

The Liberal convention in Halifax last April saw delegates adopt a resolution that supported decriminalizing all illegal drugs. The resolution put forward by the national Liberal caucus for debate at the convention called for illegal drugs to be treated as a public health issue. It also urged the government to adopt the Portugal model.

Petitpas Taylor said at the time that what works for a small country like Portugal wouldn't work in a large one like Canada.

Federal NDP Leader Jagmeet Singh urged Trudeau last fall to decriminalize all illegal drugs and he also campaigned on a promise to decriminalize all drugs during his party's leadership race.

Conservatives have been largely opposed to legalizing pot and would object to the idea of decriminalizing even harder drugs.