Nine people died from fentanyl opioid overdoses in the Canadian city of Vancouver in just the past 24 hours, Mayor Gregor Robertson said Friday.

The spike in deaths comes as Canada - like its neighbour the United States - has been struggling to contain an overdose crisis that claimed 2,000 lives last year, with even more expected in 2016.

Flanked by the city's police chief and other emergency officials, Robertson lauded existing harm reduction services such as drug consumption rooms in the city, but said more treatment options are urgently needed.

"It's desperate times in Vancouver and it's hard to see any silver lining right now when we haven't hit rock bottom," he said, warning of more overdoses to come.

"Can you imagine nine people dying from another cause in one day in our city?" Police Chief Adam Palmer said, calling for more help for addicts.

The government has poured tens of millions of dollars into bolstering public health emergency responses, with little effect.

Across the border, the United States has also seen a sudden spike in fentanyl-related deaths, including the apparent overdose of the pop star Prince in April.

Vancouver has seen an average of 15 overdoses a month and police are currently investigating 160 fatalities, Palmer said.