Prime Minister Justin Trudeau says he made substantial progress during his four-day trip to China even though he failed to secure an agreement to begin formal negotiations on a comprehensive trade deal with the world's second-largest economy.

Those talks, specifically the failure to advance past the exploratory stages, dominated both his meetings in Beijing with senior Chinese officials, and his appearance in Guangzhou at the Fortune Global Forum, attended by some of the most powerful business leaders in the world.

It also dominated Trudeau's news conference with reporters before his return flight to Canada.

The prime minister acknowledged the difficulties dealing with a country that doesn't share the same commitment to democratic ideals. But when asked during an armchair discussion at the conference if that's generating pushback from Canadians, Trudeau said there are always challenges no matter who's on the other side of the table.

China remains a big prize

"What Canadians expect as we engage with trade — and particularly a country as significant and as much of an economic powerhouse as China has become — is that they need to be assured that the values, the interests and the jobs Canadians hold dear are going to be compatible and fit within that trade deal."

China's economy dwarfs Canada and in 2017 is expected to grow at roughly double the pace.

Trudeau is given a tour of the Chen Clan Academy in Guangzhou. (Sean Kilpatrick/Canadian Press) With NAFTA talks stalemated over U.S. President Donald Trump's demands for major concessions, and the growing possibility that the deal might be scrapped, Canada is looking to diversify its trade relationships.

The Trudeau government already has a free trade deal in place with the European Union, but China remains a big prize.

Trudeau acknowledged that concerns about China's human rights record, and its use of state-owned enterprises to invest heavily around the world, present challenges.

"That has particular implications when you have state-owned enterprises competing in the same sphere as private enterprises," he said. "Any discussion on trade as we move forward needs to reflect on the challenges, the opportunities, the advantages and the inconvenience when two systems that are different are trying to collaborate so we can create benefits for both groups of citizens."

Trade, while dominant, wasn't the only topic raised during the visit.

Trudeau said he spoke to President Xi Jinping about the upcoming meeting that Canada is co-hosting in the new year with the United States to increase diplomatic and political pressure on North Korea.

"I had a good conversations with President Xi about this ... and I look forward to continuing conversations with our American partners who have a continued role to play in the peace process that we would like to see get underway in North Korea but we still have a lot of work to do before that."

Detained wine merchant discussed

The prime minister said he also raised a number of cases involving Canadians who've been detained in China.

"Canadians expect that I stand up for them and I can assure you that I've raised consular cases with the leadership that I met," he said when asked what progress had been made in trying to win the release of Canadian wine merchant John Chang who's been jailed over a customs dispute.

Trudeau stressed the benefits of liberalized trade throughout the trip. (Sean Kilpatrick/Canadian Press)

His daughter had urged Trudeau not to increase ties with China until her father is freed.

"I specifically brought up that particular case because I know it's one that Canadians are following very closely."

Trudeau stressed Canada-China ties

Throughout his visit Trudeau spoke of the shared ties between Canada and China, positioning them several times in the context of what he called growing populism and nationalism in other parts of the world.

While he never mentioned Trump, he made it clear that Canada and China share a belief that openness and more liberalized trade around the world is an antidote to those forces.

"What we've actually seen over the past decades in many places is that people are wondering when the benefits are going to reach them. The middle class is stalled in a lot of Western countries and people are starting to withdraw their support for pro-growth policies," he said at the conference.

"And that's when we start seeing the spikes in nationalism and protectionism."