Prime Minister Justin Trudeau's invitation to the East Asia Summit, a key forum for regional and global security discussions, is a sign Canada's aggressive overtures in the region have paid off, Foreign Affairs Minister Chrystia Freeland said Sunday.

Canada has been invited to the summit for the first time as an observer, officials said, and Trudeau will be privy to high-level talks, alongside the likes of Chinese President Xi Jinping, on the tenuous security situation in North Korea.

"This is the first time Canada will be present ... that is a really big deal," Freeland told reporters about the two-day summit in Manila that starts Monday. "The East Asia Summit is the top table in Asia on security issues. Canada has never been there before, so when the prime minister says 'Canada is back,' the fact that he has been invited ... is a very, very important sign of that.

"Our government is acting on our pledge that 'Canada is back,' and the world is recognizing that," she said.

Canada will formally ask to join the summit — which is held every fall and coincides with the annual Association of Southeast Asian Nations (ASEAN) leaders' meeting — as a permanent member, something that could prove elusive as membership has only been expanded a handful of times since its creation. In 2011, the last year there were additions, the U.S. and Russia were invited to join. The summit's 18 members must reach a consensus on whether to lift a current membership moratorium and allow Canada to join.

Canada appointed its first ambassador to the ASEAN region, Marie-Louise Hannan, following the recent appointment of envoys to Cambodia and Laos, also firsts, meaning Canada has diplomatic representation in all East Asia Summit member countries.

When he was U.S. president, Barack Obama attended every East Asia Summit — except one, when he faced a federal government shutdown in 2013 — as he saw the EAS as the best forum to assert American influence on Asia-Pacific affairs.

In an interview with CBC News before Trudeau left for his Asian trip, Philippines Ambassador to Canada Petronila Garcia said the other members of the East Asia Forum are ready to give Canada a chance to make its case for membership.

President Donald Trump toasts Philippines President Rodrigo Duterte, right, at an ASEAN Summit dinner in Manila. Duterte invited Prime Minister Justin Trudeau to take part in the high-level East Asian Summit (EAS). (Andrew Harnik/Canadian Press)

"They're interested in joining ... and [being invited as an observer] will provide them a venue to express their points," she said.

Philippines President Rodrigo Duterte, who is hosting ASEAN leaders amid a brutal anti-drugs campaign in his country that has ignited human rights concerns, invited Trudeau to attend.

Canada sees opening in Asia as Trump retreats

Canada sees an opening to bolster its standing in the region as U.S. President Donald Trump continues creeping towards isolation, pursuing a retrenchment of sorts from Asia-Pacific.

For example, in a speech to APEC delegates this week in Danang, Trump warned he will continue to pursue an "America First" agenda and shun multilateral trade deals like the Trans-Pacific Partnership (TPP).

Moreover, American officials were largely absent from ministerial level talks at the APEC summit in Vietnam last week, whereas Freeland, and International Trade Minister François-Philippe Champagne, were busy glad-handing their Asian counterparts, mostly in the pursuit of a renegotiated TPP, but also to strengthen fledgling bilateral ties.

Trump seriously considered skipping the ASEAN summit altogether, before finally deciding to tack on a couple of extra days to meet with his southeast Asian counterparts. "I think that he heard from friends and fellow leaders who said, 'Hey, why don't you stay an extra day…,'" a senior Trump administration official said in a briefing with reporters. "It happened in a conversation. He said, 'Let's do that, let's do that.'"

Joshua Brown, head of the Canada-ASEAN Business Council, said Canada needs to capitalize on this rare moment in time.

"That political event [the U.S. drift towards isolation] is creating opportunities for us that we should take advantage of," he said in an interview with CBC News.

The ASEAN market countries have "huge populations with increasingly large middle classes that are hungry for the types of high-quality products that Canada produces," he said.

Lobbying for UN Security Council seat

Canada is in the throes of an aggressive diplomatic engagement with ASEAN countries, officials said, in an effort to expand economic ties and curry favour with countries ahead of a vote on a non-permanent seat on the UN Security Council.

Prime Minister Justin Trudeau holds a young girl during his visit to the Likhaan Women's Health centre in Manila. (Adrian Wyld/Canadian Press)

Freeland raised Canada's bid for a seat with her Australian counterpart while at APEC. She will ask others to support Canada's pursuit of a seat during bilateral talks here in Manila.

While the TPP faces an uncertain future, Trudeau also will push ahead with exploratory talks on a Canada-ASEAN free trade deal while at the summit this week.

As a group of countries, the 10 member ASEAN states represent Canada's sixth largest trading partner.

ASEAN includes Singapore, Brunei, Malaysia, Thailand, Indonesia, Vietnam, Philippines, Laos, Cambodia and Myanmar.

"Having the prime minister here, at their 50th anniversary of ASEAN ... is a great way to kick those talks off, and I've already heard from many ASEAN leaders how much they appreciate that," Freeland said.