Justin Trudeau was tugged between dual loyalties spanning the Atlantic Ocean as he committed Tuesday to working with the United States and Europe for the economic good of all Canadians.

In the end, he sided subtly with Europe, in the stormy transatlantic rift that emerged between the continent and the U.S. following President Donald Trump's debut at the G7 and NATO summits.

"We will always work together and highlight the shared values that are equally important on both sides of the Atlantic, including in the United States," Trudeau told reporters as he wrapped his trip to Italy, following his appearance at the two summits.

He also pledged his ongoing support for the Canada-EU free trade deal and a commitment to fight climate change as ways to create jobs.

Though Trump is no fan of liberalized trade or climate change accords, Trudeau made clear he would defend the merits of both by continuing to argue — as he has tried to constructively with Trump — that both are good for economic growth.

"The way we can work on that together where we have discussions, where we agree, is going to continue to be based in openness, in frankness, in robust exchanges," said Trudeau.

But it was in a speech to Italy's Chamber of Deputies that Trudeau unleashed his most severe public criticism of Trump to date, said Stephen Saideman, a foreign relations expert at the Norman Paterson School of International Relations at Carleton University.

Trudeau noted the anxiety created by "the twin forces of technology and globalization," and said those forces can be harnessed to help deal with problems like climate change.

"Leaders who think we can hide from these changes, or turn back the clock, are wrong," Trudeau declared.

Saideman called that a clear criticism of Trump, one that aligns Trudeau with German Chancellor Angela Merkel's post-summit disappointment with the president.

"It's sort of putting Trump into the dinosaur category," said Saideman.

"He's been resistant to being pushed by the NDP or by members of his own party to speak out strongly against Trump. Now we see him taking a cautious stance, but still a pretty clear stance."

Making nice with Trump

Merkel suggested there has been a disappointing shift in relations between Europe and the U.S. after the continent couldn't reach a climate change deal with Trump at the G7. Merkel said the time had come to for Europeans to "take our destiny into our own hands.

Unlike Merkel, who faces an election later this year and won't win votes if she sides with Trump, Trudeau must build bridges with the mercurial U.S. president because Canada is economically intertwined with its No. 1 trading partner.

Canada will join the U.S. and Mexico at the bargaining table later this summer to renegotiate the North American Free Trade Agreement.

Saideman said the Trudeau government can still tend to its all-encompassing economic relationship with the U.S. by continuing its full-court political press on all levels of government, including the two houses of Congress.

"The reality is most of the damage that Trump can do, in terms of trade, can only be done with the consent of Congress, so Canada's in good shape because they've got allies in Congress."

German Chancellor Angela Merkel, center left, greets Trudeau as they attend a round table meeting of G7 leaders and partners at the G7 summit in Taormina, Italy, Saturday. (Domenico Stinellis/Associated Press)

Trudeau also found himself offside with Trump at the NATO summit in Brussels, prior to his arrival in Italy. Trump blasted 23 of NATO's 28 members for not spending enough on the military alliance to meet its two-per-cent of GDP target, a group that includes Canada.

The government presents its long-awaited defence policy review next week, but few are expecting it to contain a major spending boost.

Dave Perry, senior analyst with the Canadian Global Affairs Institute, said he doesn't think Canada will be making any changes to the document after the NATO summit.

He predicted strained relations between NATO and the U.S. going forward, but suggested that Trudeau is still well placed to act as an "interlocutor" between the two groups because he still has a more constructive relationship with Trump than most other leaders.