Republican presidential hopeful Donald Trump doesn't hesitate to shoot from the hip on a host of public policy issues, but his comments Wednesday about the efficacy of NATO have reverberated throughout defence circles and could have consequences for Canada.

At the core of his criticism of the multilateral alliance is that the United States foots the bill for far too much of the alliance's defence capacity, and other member nations — including Canada — are "freeloaders" for failing to contribute their fair share of domestic military spending.

"It's obsolete and too many people are getting a free ride," Trump said Tuesday night after racking up lopsided victories in five presidential primaries.

"Frankly, they have to put up more money. We are paying disproportionately. It's too much. It's a different world than it was when we originally conceived of the idea."

He has also argued that NATO does not adequately address the pressing problems of our time, notably Islamic terrorism, but is instead focused on an older adversary, Russia, and its continental encroachment.

He doubled down Wednesday, during one of his first scripted policy speeches in Washington, saying that if NATO allies don't meet the spending targets they should get out of the alliance and defend themselves against security threats without relying on American firepower.

"The countries we are defending must pay for the cost of this defence, and if not, the U.S. must be prepared to let these countries defend themselves. We have no choice," he said.

Republican presidential frontrunner says U.S. can't foot the bill for other NATO allies, calls on them to boost to defence spending. 0:48

Defence review to consider spending boost

Canada's Defence Minister Harjit Sajjan said Wednesday that meeting NATO's spending target of two per cent of GDP — something that Canada agreed to in 2006 — is still under consideration.

"This is a discussion we're going to have as part of the defence review," Sajjan said, adding that money alone does not accurately measure Canada's military contributions. "The defence review is also going to allow us to have that conversation about what direction we need to go. We are committed to working with our multilateral organizations, and NATO is a part of that."

Defence Minister Harjit Sajjan respomds to a question asking if Canada will raise it's defence spending to 2% of GDP as requested by NATO. 1:13

Canada signed on to meeting that target but that promise looks disingenuous in retrospect. Canada's spending comes in at just one per cent of GDP, or roughly $20 billion a year, a figure that many argue is simply too low to sustain a fine fighting force. Indeed, only five other countries of the 28 in NATO spend less.

In the short term, Canada is inching no closer to meeting its goal. The 2016 budget deferred some $3.7 billion in spending for capital projects by five years. The Harper government, too, let billions in planned military spending lapse.

The military spending shortfall from non-U.S. NATO allies has left some member countries wholly dependent on the Americans for key military functions, something that could be mitigated by more robust national military budgets.

"There is an over-reliance by the alliance as a whole on the United States for the provision of essential capabilities, including for instance, in regard to intelligence, surveillance and reconnaissance; air-to-air refueling; ballistic missile defense; and airborne electronic warfare," NATO officials wrote in a recent policy paper on national funding.

Trump, Obama on the same page

It's not just the decidedly non-interventionist Trump — a man who has had trouble naming any of his foreign policy advisers — who has taken aim at countries that are failing to meet the spending target. In fact, he is on the same page with an unlikely ally: the current president.

"Free riders aggravate me," Obama said in a recent, in-depth interview with The Atlantic magazine.

As recently as last year, the president warned the United Kingdom that it would no longer be able to claim a "special relationship" with the U.S. if it failed to spend at least two per cent of its GDP on defence.

"You have to pay your fair share," Obama told British Prime Minister David Cameron. In last year's budget, Britain subsequently met the target despite an emphasis on austerity in other areas of program spending.

U.S. President Barack Obama has said he doesn't like military 'free riders,' something that could include Canada, which lags behind the NATO goal of spending two per cent of GDP on defence. (Jim Watson/Agence France-Presse)

It's not known if Obama has raised Canada's comparatively low levels of military spending with Prime Minister Trudeau, but the country's defence budget has not gone unnoticed by others in the capital of our closest partner, including liberal-minded Democrats in Congress.

"The prime minister has committed to up the ante for Canada's presence in the world," senior U.S. Senator Amy Klobuchar told CBC Radio's The House during a recent visit to Washington, and that should include boosted military spending.

"I know you have your own economic issues with oil prices down and other things ... but I do think that it would be good if Canada would invest a bit more — and I love that two per cent number," the senator said, identifying it as one of the few sticking points between the two countries.