Prime Minister Justin Trudeau isn't committing to the sale of marijuana in liquor outlets, as Ontario Premier Kathleen Wynne and others have suggested, but he isn't ruling it out.

During a visit to Vancouver City Hall on Thursday – the first by a sitting prime minister since Mr. Trudeau's father, Pierre, visited in 1973 – Mr. Trudeau said he is open to all "best practices" on the issue as he forges ahead with his commitment to legalize and regulate marijuana.

Federal Justice Minister Jody Wilson-Raybould, a Vancouver MP who accompanied Mr. Trudeau on the visit, said there is no specific deadline for completing the legalization process.

Story continues below advertisement

"I am not going to commit to a timeline because we want to ensure that we approach it in a comprehensive way, ensuring we speak broadly with other levels of government," she told reporters.

Asked about selling pot through liquor stores, Ms. Wilson-Raybould said she appreciated that Ontario's Premier and others are expressing their ideas, and she looks forward to working with all provinces and stakeholders.

As for whether criminal charges would be laid ahead of legalization, she said marijuana remains illegal at this time.

Mr. Trudeau received an effusive welcome at City Hall, with dozens of municipal staff, elected officials, senior police and fire officials, and members of the public lining up outside to await him and filling the cramped main hall.

The Prime Minister met with Vancouver Mayor Gregor Robertson, whose government struggled this year to manage a boom in medical marijuana dispensaries – an effort that was sharply criticized by the former Conservative federal government.

"When it comes to distribution, when it comes to selling, obviously the provinces and, indeed, the municipalities will have to be an integral part of that discussion and we're expecting there to be different perspectives and different solutions put forward," Mr. Trudeau said.

"The challenge of getting this important initiative right is one of ensuring we are broadly listening to partners, to folks in the medical marijuana industry, to municipal partners, to provinces and drawing from best practices from around the world," he said. "We're going to get this right in a way that suits Canadians broadly."

Story continues below advertisement

In a subtle jab at the former Conservative government, Mr. Robertson said the city had no choice but to step in to regulate dispensaries because "there was no thoughtful controls coming from Ottawa."

But he said it was too soon to be specific about how to regulate marijuana, beyond saying Vancouver would take and apply lessons from managing dispensaries to the new regime that would be created by Ottawa.

"It remains to be seen," he told reporters after Mr. Trudeau had departed. "We need to understand what the options are. We see different approaches in different states south of the border. We want to make sure we have all the facts in front of us before we make any decisions around distribution."

Earlier this year, Vancouver introduced a business licensing system to regulate medical marijuana dispensaries, which have proliferated in the city despite remaining illegal under federal law.

This week, Ontario's Ms. Wynne called for marijuana to be sold through government-owned liquor stores in her province, suggesting the liquor-distribution mechanism could responsibly sell the drug. Her comments followed those of the union representing workers in government-owned stores in B.C. in a partnership with the B.C. Private Liquor Store Association, who support a similar approach.

Independent Senator Larry Campbell, who, along with all Liberal senators, was expelled from the caucus two years ago, said legalization is well below other priorities of a government that is "just trying to get their feet on the ground and get their staff together."

Story continues below advertisement

"I don't think it's really on their radar yet," he said from his home on Galiano Island on Wednesday. "We're looking at two years down the road before we get to some form of legalization."

Mr. Campbell, who pushed for harm reduction on the Downtown Eastside when he was Vancouver's mayor, said the government should first fix the failing medical marijuana system, where fewer than two dozen licensed producers are restricted to mailing their product to a patient base of roughly 18,000 people.

"You could actually set up a bank in this country with less regulations from the point of view of security and all the rest of it," said Mr. Campbell, who is an adviser to aspiring pot grower Vodis Innovative Pharmaceuticals Inc.

"From the start, I don't think the [former Conservative] government was supportive of [the federal medical marijuana system] and the bureaucracy was caught in the middle, quite frankly."

He said the federal government should create retail avenues for medical marijuana producers to sell their product to customers.

With a report from Mike Hager