That uncertainty has been created with U.S. president-elect Donald Trump and his anti-trade rhetoric set to take over the White House, potentially leaving a leadership vacuum on the world stage.
Trump's anti-trade stance shook up the agenda of the APEC leaders' annual meeting, forcing them to speak of the public relations war they now must wage to convince their citizens that trade has worked for them.
Trudeau said trade deals needed to spread benefits to more Canadians because the beneficiaries of the pacts over the last 30 years have largely been higher-income earners, "and I think that's wrong.''
The final declaration from the 21 leaders of Asian and Pacific countries speaks of keeping borders open to trade, avoiding currency manipulation and devaluation, and ensuring that everyone benefits from economic growth because not all countries and sectors have rebounded equally from the 2008 global financial crisis.
Trump has referenced each of those as issues he wants addressed in trade deals that he believes are unfair for the American economy.
Prime Minister Justin Trudeau and New Zealand's Prime Minister John Key listen to Australia's Prime Minister Malcolm Turnbull on Sunday in Lima.
"This is not based on ideology or opinion, this is based on the fact that Canada has benefited extraordinarily over the almost 150 years of our existence _ and well before that _ from strong trading relationships with the Americans and indeed with the world,'' Trudeau said, pointing to the auto sector.
But the prime minister is leaving Peru without a commitment from U.S. President Barack Obama on the ongoing softwood lumber dispute - "the American lumber industry has a large say in how this is going to unfold. Indeed they have a veto over what the administration might propose," Trudeau said.
Trudeau also didn't say whether he would lobby Trump to approve the Keystone XL pipeline, which the president-elect has spoken of fondly.
All Trudeau would say about the man who dominated the agenda at the APEC leaders' summit was an echo of what Obama has said this weekend: The realities of global economies will turn Trump away from killing trade deals like the North American Free Trade Agreement.
"The level of integration and inter-dependence between the Canadian and American economies on many levels, for me is the strongest proof point that trade has been good for both of our economies and will continue," Trudeau said.
Earlier in the day, the outgoing president tried to ease concerns that the Liberal prime minister would clash with the Republican president-elect who has threatened to tear up the NAFTA unless he gets concessions from Canada.
"Through Conservative governments, Liberal governments, Democratic or Republican governments, the relationship between the United States and Canada is one of the most important constants in the world and I have no doubt that will continue," Obama said.
U.S. President Barack Obama and Prime Minister Justin Trudeau.
Obama used his last international summit to calm the nerves of world leaders, and keep on track a Pacific Rim trade pact designed to act as a counterbalance to China's growing influence in Asia in the face of Trump's threats to cancel the deal.
The Trans-Pacific Partnership would cement free trade among 12 nations encompassing nearly 40 per cent of the world's GDP, including Australia, Canada, Mexico, Japan and the United States. The deal cannot come into force without the approval of those latter two countries.
During a closed-door session Saturday with TPP members, Obama urged them not to give up on the deal.
Leaders in the room voiced support for moving ahead with trade pact if the stars aligned in the coming months, and no country said it was ready to walk away from the agreement, according to international officials who were in the room, but not authorized to speak publicly about the talks.
Trudeau said he wouldn't jump to any conclusions about what Trump will do with TPP once in office, saying the Liberals are "keeping our options open.''
"The level of integration and inter-dependence between the Canadian and American economies on many levels, for me is the strongest proof point that trade has been good for both of our economies and will continue."
And in one of his last face-to-face meetings with a world leader, Obama sat next to Trudeau and spoke about the work the two have done on refugees and climate change. Trump has vowed to roll back environmental funding and put in stricter immigration rules.
Obama praised Trudeau and said he looked forward to the prime minister's continued leadership on those issues in the coming years.
Obama said he and Trudeau are going to try and get as much work completed on thinning the borders during the last two months of his presidency.
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