ANTALYA, Turkey -- Justin Trudeau used his international debut Sunday to tell a top tier G20 business audience that long-term investments in infrastructure and youth are the keys to growth, not a preoccupation with short-term profits.

And as the prime minister reaffirmed Canada's commitment to accept 25,000 Syrian asylum seekers, he delivered a pointed message that Canada is a country that defines itself by its shared values, not its cultural differences, and he urged others to do the same.

But even before he opened his mouth, Trudeau received a welcome on the floor of the G20's business and labour panel discussion that lived up to the cliched rock-star-welcome descriptor.

He was mobbed for selfies by dozens of smiling delegates at the meeting shortly after his arrival. Trudeau willingly posed for several minutes, allowing many selfies and group photos at the foot of a stage, prior to giving a speech and taking part in a panel discussion before an amphitheatre of more than 100 invitees.

Not everyone wanted a photo, but many others approached Trudeau as he held court, receiving warm greetings from a variety of people, including Christine Lagarde, the managing director of the International Monetary Fund.

Canadian Mark Carney, the Governor of the Bank of England, was among those in attendance, along with Perrin Beatty, president of the Canadian Chamber of Commerce and Angel Gurria, the secretary general of the Organization for Economic Co-operation and Development.

Trudeau covered ground that would have been familiar to Canadians following the federal election, including his infrastructure spending plans to stimulate growth.

But he also explained why he appointed himself as the cabinet minister for Canadian youth -- a first for a prime minister, he said -- while sending a message that global audiences have not heard from a Canadian prime minister in about a decade.

"Climate change is a very real challenge, and how we prepare for the increasing pressures on our ecosystems and our resources and our climate will be something that we will be judged on in coming decades and generations."

Climate change, along with the fight against terrorism and the refugee crisis, are on an expanded G20 agenda at this two-day leaders' summit in Antalya, Turkey.

Trudeau, however, also moved quickly to align Canada, as expected, with a core G20 theme: stimulating economic growth through spending on infrastructure.

"Canadians sent me a strong message over the course of our election campaign. They felt that it was important we be investing in our communities, we be investing in infrastructure," he said, adding that kind of "inclusive growth" was good not only for Canada, but the world.

Trudeau urged governments, community, business and labour leaders "to focus on the meaningful long-term solutions, to empowering individuals and creating prosperity."

"It is tempting to look at quarterly returns and short term outcomes and think that if everyone just takes care of the short-term the long-term will take care of itself. That is increasingly not true," he said.

Trudeau fielded two questions from the audience, on topics that touched on soaring youth unemployment and refugees.

He noted that since he started his career as a school teacher he has recognized the wider benefits of helping young people become more successful, "which is why for the first time the prime minister of Canada is also the minister for youth of Canada."

"This isn't a sentimental choice," Trudeau added. "This is something that recognizes the fact that the success of our young people will determine the success of not just of our economies, but indeed of our planet."

Trudeau said he intended to retain Canada's youth ministry because it overlaps with business, health, employment and international relations.

When asked about refugees, the prime minister offered some observations on what he feels are the benefits of Canada's cultural mosaic.

"Canada figured out a long time ago that differences should be a source of strength, not a source of weakness," Trudeau said.

He suggested a country should not be defined by "national identity or ethnicity or language or background but on values," such as openness, respect, compassion, "a willingness to work hard and be there for each other."

Trudeau said this is "going to be the norm rather than the exception" in a globalized world, driven by migrations and immigration.

"This is a lesson we all need to learn," he stressed.

Trudeau also held bilateral meetings with Indonesian President Joko Widodo and announced a $14 million infrastructure project for the South Asian country. He later met with Mexican President Enrique Pena Nieto.