The federal government has denied Toronto's request to decriminalize simple possession of small amounts of drugs for personal use, saying it "does not adequately protect public health and maintain public safety."

"This includes concerns with feasibility and ability for law enforcement to implement the proposed model, protection of youth, and lack of support from key players including the Province of Ontario," Minister of Mental Health and Addictions Ya'ara Saks said in a statement released Friday afternoon.

Ottawa's decision came a day after the Ontario government urged the city to drop the request, which it called "misguided" and "disastrous."

Health Minister Sylvia Jones and the province's Solicitor General Michael Kerzner indicated in their letter to Dr. Eileen de Villa, Toronto's medical officer of health, that the province will not support the request made to Health Canada in early 2022 for an exemption under the Controlled Drugs and Substances Act.

Premier Doug Ford also reiterated that his government would not back the request in his letter to Prime Minister Justin Trudeau on Thursday, in which he asked Ottawa to pause the approval of new safe supply sites.

"As we've already indicated to Toronto Public Health, we do not, and never will, support their application to decriminalize illegal drugs," Ford wrote. "Please consider this our formal confirmation to the federal government that we are 100 per cent opposed to their proposal."

Ford's comments come in tandem with federal Conservative Leader Pierre Poilievre, who also recently penned a letter to the prime minister asking him to reject Toronto's request.

Toronto's drug decriminalization request returned to the spotlight after British Columbia's request to recriminalize the use of select drugs in many public spaces following problems which arose from an exemption order previously granted to the province,.

Dr. de Villa, in a statement Friday evening, said now that decriminalization, which she called as just one "evidence-informed policy tool", was no longer an option, "the need to invest in other available evidence-based interventions is all the more critical."

"Increasing funding and access to a broad range of treatment options, which is the responsibility of the province, is another tool required to address the drug toxicity epidemic," she said.

De Villa told CP24 Thursday that the request represents her best medical advice for public health. "At the end of the day, I will continue to do my job as a physician to provide the advice and then to leave the decision-making to the elected officials," she said.

In her Friday statement, she voiced her support for Toronto Mayor Olivia Chow's call for partnership between all levels of government to address the "complex epidemic."

"Toronto Public Health remains a ready and willing partner to explore collaborative approaches on this important and urgent health issue," de Villa said.

Before the federal government's decision was announced on Friday, Chow, in a letter, urged all three levels of government to work together on points of agreement to combat the opioid crisis.

She said the approach should include a 24/7 Crisis Centre; expanding access to evidence-based treatment for substance use; supportive housing to address complex needs; and other measures.

"I believe this approach, with a strong focus on expanded treatment options, can significantly reduce the devastating impact of the drug toxicity epidemic in Toronto and across Ontario," Chow wrote.

She also said, "We all agree more treatment is vital."

Chow has previously said she thinks the debate about decriminalization is irrelevant without proper housing and treatment supports in place for people addicted to drugs.

With files from Codi Wilson and The Canadian Press