Canadians and Americans may disagree about the appropriate level of defence spending, but a new report says they do have one thing in common — they like NATO more than they did a few years ago.

New research by the Pew Center, a U.S.-based, nonpartisan think-tank, suggests increased public support for the transatlantic alliance, despite the political bashing it took from Donald Trump in the run-up to last year's presidential election.

The report comes just as NATO leaders, including Trump and Prime Minister Justin Trudeau, gather in Brussels to inaugurate the new headquarters building.

It's unclear how much of the upturn in support is the result of the public in other countries thumbing their nose at Trump and how much relates to the threat from a resurgent Russia.

What is apparent from the study, released Tuesday, is that opinion of NATO in the U.S. has been polarized by the new president.

"Behind the overall uptick in favourable views of NATO, there are sharp political and partisan differences in how publics in member countries perceive the alliance," said the report, which noted a substantial drop in support among Republicans since the last survey in 2015. It was, however, more than offset by a surge in favourable views among Democrats.

By contrast, Canadians have, uniformly, fallen in line behind the military alliance, with nearly two-thirds of those asked holding a favourable view.

That is an increase of 10 per cent in two years. The sentiment is broadly shared by Liberals and Conservatives and somewhat reluctantly endorsed by New Democrats.

Trudeau leaves for NATO Summit in Brussels 1:17

Trump doubts on NATO

Public opinion in most countries seems to have shrugged off Trump's remarks during the presidential campaign when he called NATO "obsolete" and raised doubts about coming to the aid of allies.

A majority believe Washington will still live up to Article 5 — NATO's self-defence clause — in the event of a major attack by Russia.

The Pew Center study says it is major European nations, notably Germany and France, who would be reluctant to send troops to help another alliance member.

In Canada, 58 per cent say the country should step up if a member was threatened.

"Public support for living up to the Article 5 commitment is generally much stronger among those who believe Russia is a major threat to their country, compared to those who say Russia poses no threat," the study says.

The challenge for Trudeau, in light of those numbers, will be to convince allies that his Liberal government is as serious as the public is about supporting the alliance.

No public shaming

Those expecting public fireworks, particularly on the sticky issue of defence spending, might be disappointed, says one defence analyst.

"Don't expect the U.S. to really call out Canada individually and publicly. That is not how diplomacy works," says former colonel Lee J. Hammond, a defence analyst, whose last job in uniform was strategic planning for the Canadian military.

"Canadians will never hear the real comments — that will all happen behind closed doors," says Hammond. "However, with a president that is focused on American first, and who views the world in pretty black and white terms, Canadians should expect "linkage" to other issues of concern like trade, immigration and open markets. If we are not pulling our weight on defence spending, the Americans will care, and President Trump will hold it against us, I expect."

Trudeau is going to NATO largely empty-handed.

Release of the long-awaited defence policy has been parked until June 7 and awaits a speech by Foreign Affairs Minister Chrystia Freeland, who will place Canada's military within the country's overall foreign policy goals.

Liberal insiders have made it widely known that allies, including the U.S., Britain and Australia, have seen the "broad strokes" of the defence plan.

The latest Liberal budget postponed billions of dollars in purchases of defence equipment, and the government, at the moment, has only paid lip service to the notion of increased defence spending as Trump has demanded.

Significant investment needed

Defence Minister Harjit Sajjan faced a series of tough questions Tuesday before the Canadian American Business Council in Washington.

He told business leaders that the Liberal government recognizes spending in the military has been "running at a deficit" and that "significant investment is needed."

But Sajjan also reminded them of the heavy burden undertaken in Kandahar and about the leading role Canadian troops will play in the upcoming NATO deployment in eastern Europe.

David Perry, a defence analyst at the Canadian Global Affairs Institute, is not sure how much weight that argument will hold with allies, including the U.S.

In the absence of the defence policy, the bar for success at the summit is set pretty low, he says.

"If it's not a disaster, it's a success," Perry says.