China was top of mind for Justin Trudeau during a visit from Japanese Prime Minister Shinzo Abe this weekend.

The two leaders met in Ottawa to commit to further the business relationship between the two countries. It was a chance to tout their strong relationship in the face of trade woes with Canada's two biggest partners, but it's clear Trudeau's focus was elsewhere.

During an appearance with Abe, he spoke about the diplomatic relations between "Canada and China," before quickly correcting himself. Later on, he accidentally referred to Japan as China again.

China's detention of Canadian citizens and its blocking of canola shipments came up during the meetings between the leaders.

Two Canadians, Michael Spavor and Michael Kovrig, have been held in China since December. Japanese citizens are also regularly imprisoned in China, and Abe said Japan has been monitoring the situation with the detained Canadians.

On the trade front, China recently cancelled canola imports from Canada, claiming the product from two Canadian companies is contaminated, though it did not provide any evidence to officials. It's a blow to farmers here, as China buys 40 per cent of this country's canola exports.

Trudeau briefly mentioned that he and Abe had discussed potentially sending some canola to Japan instead. Canada's exports to Japan nearly topped $13 billion in 2018, versus exports of $27 billion to China, according to Global Affairs.

Japanese officials said Trudeau had raised it and Abe listened, but the conversation didn't go beyond that.

The two prime ministers, their ambassadors, several Japanese ministers, plus Canadian ministers Bill Morneau and Chrystia Freeland were part of the official delegations that met Sunday morning.

Trudeau and Abe had a short meeting before the larger gathering, as well as a 90-minute private dinner Saturday night with their spouses and interpreters.

Trudeau said, while the two countries engage economically with China, both have to be wary of China's attempts to "impose" its approach on the world.

Convincing China to play a constructive role

Abe took a softer approach, saying that Japan agrees with Canada about human rights and rule of law, but it's important to try to foster international ties with China. He was frank about the challenges.

"Canada and Japan are facing challenges when it comes to China," he said through a translator.

"The global community must unite and convince China to play a constructive role."

That's an increasingly hard goal, as longstanding rules-based systems, like the World Trade Organization, are tested by players like China and the U.S. — both countries with leaders who aren't inclined to play by the established rules.

"Obviously with issues like the rise of China and the approach that the United States has taken recently, there are real challenges," Trudeau admitted.

The Trump administration's approach to trade has caused headaches for the Liberal government, as issues negotiating a new NAFTA agreement and tariffs on steel and aluminum put the North American countries at odds.

Abe and Trudeau devoted much of their remarks to hailing the benefits of the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), the new trade deal for 11 Pacific Rim nations that was revived and ratified after the U.S. backed out following Trump's election.

Canada is 'stark contrast' to the U.S.

Trudeau said the gains Canada has been able to make, including upping beef and pork exports to Japan, show Canada "stands in stark contrast," to the approach of the U.S.

Abe was in Washington meeting with Trump directly before he flew to Ottawa. He refrained from taking the same firm tone as Trudeau about the U.S.

"I think that we share the same position, but we should co-operate together so that the United States will be encouraged

to be the leader of the liberal free world and we will co-operate with Canada," he said.

Trudeau and Abe signed two memorandums that agree to invest more in robotics and AI between the countries, as well as an announcement that Canada would recommit to devoting resources to monitor North Korean activity in Pacific waters.

Japan will host the G20 summit in June and Abe and Trudeau will likely meet again at the G7 gathering in France in August.