Canada's new Liberal government is pushing its pot-friendly ideas on the rest of the world, and one government backbencher hopes the country could be a driving force in getting the United Nations to reconsider its treaties that ban the drug.

Ottawa might not have a choice, as it finds its plans to legalize marijuana at odds with three UN treaties on the matter.

"If Canada can do this right, and we can build up evidence to show that regulation of marijuana works in a way that prohibition doesn't, we have an opportunity to lead by example."

Nathaniel Erskine-Smith, an MP for a riding in Toronto's east end, argued alongside a senator from Mexico that all nations should pursue alternatives to imprisonment for people caught possessing marijuana for personal use.

"Resources better spent on healthcare are now being spent on incarceration, and incarceration alone is redirecting people away from healthcare," Erskine-Smith told hundreds of government representatives from around the world on Tuesday. "We ought not to throw scotch-users in jail, and we ought not throw the book at marijuana users."

Prime Minister Justin Trudeau has pledged to "legalize, regulate, and restrict" access to marijuana for recreational use in Canada, though the government still hasn't said exactly how or when legalization will take place.

Erskine-Smith is one of the first voices from the governing party to talk directly about the issue since Trudeau formed government in October.

"If Canada can do this right, and we can build up evidence to show that regulation of marijuana works in a way that prohibition doesn't, we have an opportunity to lead by example," he told VICE News in an interview after the debate.

At the debate, government representatives from Nigeria and Sudan voiced their opposition to progressive drug laws, arguing that incarceration for drug offences was necessary to prevent terrorism, and also to help rehabilitate offenders. Countries like these may frustrate efforts to drop marijuana from the treaties.

While the debate — held during this week's Inter-Parliamentary Union conference at the UN in New York entitled "The World Drug Program: Taking Stock and Strengthening the Global Response" — was merely an exercise, and not legally binding on nations in any way, it foreshadows a larger fight that could be brewing at the UN.

It also sets up Canada to join a chorus of nations expected to renegotiate their commitments at the UN General Assembly Special Session on drug policy in April. Other nations that have moved towards decriminalization or legalization — a handful in South America, as well as Portugal and Mexico — are expected to ask the UN to recognize the drug as, essentially, harmless.

Those three UN treaties, the earliest dating back more than 50 years, bind signatory states to combat the trafficking of a variety of drugs, including cannabis, and forbids their domestic cultivation, except for certain industrial, research, and medical purposes.

Canada, and other states looking to decriminalize or legalize the drug, will likely have to drop out of the treaties, or have them amended.

"Canada is party to three international drug conventions," reads a briefing note prepared for Prime Minister Justin Trudeau, obtained under access to information laws. "As part of examining legalization of cannabis possession and production, Canada will need to explore how to inform the international community and will have to determine the steps needed to adjust its obligations under these conventions."

Trudeau is scheduled to meet with UN Secretary General Ban Ki-moon on Thursday in Ottawa, although the agenda is unclear.

Erskine-Smith says now is the right time to tackle the problem on a global scale.

"We should be pushing for greater flexibility to experiment with public health approaches to drug regulation," he added. "[Countries] should recognize that cannabis is not as harmful as the other substances that are subject to those same conventions."

The fact that Canada was even present at the conference marks a drastic shift from the previous Conservative government, which typically brushed off participation at such UN events, and implemented a number of harsh sentences for drug offences and vehemently opposed marijuana legalization.

"It was great to have a number of countries come up to us and express their relief and satisfaction, and general positive reception, to seeing Canada be a progressive voice again at these events," added Erskine-Smith, a lawyer by trade who studied marijuana decriminalization at Oxford University.

He's been especially enthusiastic about his party's stance on pot. Last month he tweeted out thanks to an activist from BC who send all Liberal MPs a gram of weed to remind them of their election promise.

On a serious note, thousands of Canadians are charged every year for marijuana possession. A sensible policy is long overdue. — Nate Erskine-Smith (@beynate)January 5, 2016

Erskine-Smith noted that many countries have already flouted these anti-drug treaties, including Portugal, which decriminalized all drugs in 2001. And last year, Mexico made great strides toward legalizing marijuana.

"This has pushed the conventions to be more flexible already," he said. "[There's] a possibility of the conventions accommodating Canada's regulatory approach [to cannabis]."

"And the UN has been fairly bipolar on the issue of drugs," he added. "On the one hand you have conventions that are, on a plain reading, quite strict, and then you have Kofi Annan, former secretary general of the UN, coming out and saying the war on drugs has failed."

Canada's Global Affairs department wouldn't comment specifically on whether Canada would renegotiate its commitment to the treaties, saying it "would be premature," but the government will "be examining a range of issues, including its international commitments, as it decides on how to approach this."