LONDON -- Canada will heartily endorse an international declaration aimed cleaning up the oceans, Justin Trudeau said Thursday -- but the prime minister stopped short of committing his government to a burgeoning push for an outright ban on the use of plastic drinking straws.
British Prime Minister Theresa May, who sat down with her Canadian counterpart the day before in London to discuss shared priorities, has set her sights on eliminating the ubiquitous utensil as a first step toward ridding the world's oceans of so-called "convenience plastic."
Cracking down on proliferating plastics and promoting the spread of LGBTQ rights largely dominated Trudeau's first day at the Commonwealth leaders' summit, which came on the penultimate day of a three-country tour that included stops in Peru and France.
The Commonwealth summit represents a rare opportunity for Canada's prime minister to meet with and hear from 52 counterparts from six continents, most of whom share some type of link to the old British Empire.
This time around, it also allowed Trudeau to piggyback on what appears to have become a personal crusade for May, who declared at the start of the summit that she would launch consultations later this year aimed at eliminating plastic waste.
The plan would see Britain work with industry to develop more sustainable alternatives to drinking straws, as well as cotton swabs and plastic stir sticks to address what May described as "one of the greatest environmental challenges facing the world."
Such products have been under fire in the U.K. since the airing of a stunning BBC documentary that included a detailed look at the impact of plastics on the world's oceans.
As host of the summit, May also championed what is being referred to as a Commonwealth Blue Charter, which Trudeau said Canada would sign and whose principles it hopes to advance at this year's G7 in Quebec.
The charter lays out a broad vision that would see developed and developing countries alike work together to ensure the ocean remains vibrant and its use sustainable.
Trudeau, however, would not be pinned down on the question of whether Canada would follow May's lead on drinking straws.
"We know that macroplastics like straws are a significant challenge in the ocean, but we also know that both microplastics and nanoplastics represent a real challenge to ocean ecosystems," he told a news conference at the Canadian High Commission.
"We are very much looking for approaches that are going to be both substantive and impactful in the way we move forward -- not just as a single country, although Canada has the longest coastline in the world, but hopefully as a global economy."
The government last year adopted legislation banning plastic microbeads in bath and body products -- the law is scheduled to take effect in July -- but has not said when it plans to take action against other types of plastic.
When asked last month about the government's plans for plastic, Environment Minister Catherine McKenna talked about increasing public awareness, helping developing countries finance waste management policies and funding science to develop compostable plastic.
Canada is already trying to catch up to the rest of the world in dealing with plastic garbage; several other G7 nations have banned or otherwise cracked down on single-use plastic items.
It's estimated about three billion plastic bags are used in Canada each year, and anti-plastics advocates say that while most are used for less than 20 minutes each, they take hundreds of years to break down.
However, if Trudeau was noncommittal on the question of drinking straws, he was anything but on another issue: Canada's support for LGBTQ rights at the Commonwealth.
The institution, which counts 53 members from six continents, has suffered over the years from relatively low engagement by its main member, Britain.
There have been hopes for renewal with Brexit looming and the U.K. on the hunt for new partnerships to replace the European Union as its primary trading partner, but a number of Commonwealth members have troublesome track records on matters of democracy and human rights.
That includes LGBTQ rights, which Canada and the U.K. have been pressing as a priority for the organization, despite significant opposition from many Commonwealth members -- a majority of whom still outlaw same-sex activities.
Despite that opposition, which saw LGBTQ rights kept off the official summit agenda, Trudeau met Thursday with Commonwealth gay-rights activists to reassure them of his continued support.
"The LGBT issue is one of the most outstanding issues that demonstrates maybe the Commonwealth isn't as good at bringing people together around shared values and principles as we should be," he told the activists.
In an interview after the meeting, the activists -- all of them members of the Commonwealth Equality Network -- welcomed Trudeau's continued work, but lamented the continued opposition voiced by other leaders.
"I can't even get close to my prime minister or my president," said Rosanna Flamer-Caldera, network co-chair and executive director of Sri Lanka's Equal Ground rights group.
"So we need to use international platforms with help from leaders like Prime Minister Trudeau."
On Friday, Trudeau returns to Canada, but not before a closed-door Commonwealth leaders' discussion about who should succeed the Queen at the helm of the organization.
Unlike the monarchy, the position is not hereditary, though the Queen took the unusual step during her speech marking the opening of Thursday's meeting to say that she would prefer Prince Charles succeed her in the position.
Asked his preference, the prime minister responded: "I very much agree with the wishes of Her Majesty that the Prince of Wales be the next head of the Commonwealth."
It's unclear whether any other successors are being seriously considered.