Canada punches above its weight on NATO operations but should still spend more on defence, a former NATO supreme allied commander told CBC News Thursday.

"We need our allies to spend two per cent. That is an achievable goal. The United States spends about 3.5 per cent of its GDP (on defence). We need that to get more in balance," retired U.S. Navy Admiral James Stavridis said in an interview with host Vassy Kapelos on CBC News Network's Power & Politics Thursday.

NATO member countries pledged in 2014 to move toward a defence spending target of two per cent of GDP by 2024. Canada's defence spending was estimated at 1.36 per cent of GDP in 2017 and is only expected to rise to 1.4 per cent by 2024.

Stavridis, who is also dean of The Fletcher School at Tufts University, said it's unfortunate that Canada will not hit the alliance target, but acknowledged something he learned from his own time as a NATO commander — that Canada's military performs with distinction, fighting bravely in Afghanistan, Libya and Iraq, and at sea on counter-piracy missions.

"Canada has always been there with the United States and has always been there with NATO," said Stavridis. "I would like to see that hit that level. I think it would be salutary for the alliance.

"At the end of the day, however, I know that the relations between the United States and Canada militarily are going to continue to be superb."

Former NATO supreme allied commander James Stavridis tells Power & Politics that Canada is punching above its weight on NATO operations, but could do more. 3:40

U.S. President Donald Trump hammered NATO allies on defence spending at the alliance's summit in Brussels this week. The combative leader closed out the summit by claiming that member nations caved to his demand for a significant increase in their defence spending.

That claim was immediately refuted by French President Emmanuel Macron, who pointed out to journalists that the alliance communique released Wednesday recommitted NATO members to hitting the two per cent target by 2024 — a commitment they made in 2014, two years before Trump was elected.

Also responding to Trump's claim, Prime Minister Justin Trudeau told reporters at his closing press conference that Canada hadn't committed to spending any new money on defence.

Stavridis said he thinks it's probably in Canada's interest to invest in better interoperability capabilities with other allied forces — but at the end of the day the decision to increase defence spending is ultimately up to Canadians, not Americans.

Crisis averted?

Trump closed out the tumultuous two-day summit by reaffirming the United States' commitment to the nearly 70-year-old alliance and signing the joint declaration, despite spending much of the summit berating allies over defence spending and accusing Germany of being beholden to Russia because it buys Russian natural gas.

"You've heard about a bull in a china shop. We've just seen a bull in a NATO shop and a lot of china got broken, I think particularly between the United States and Germany. That's very unfortunate," said Stavridis.

Former NATO supreme allied commander James Stavridis tells Power & Politics that Trump's performance was rocky, but the trans-Atlantic alliance holds together, for now. 1:56

The retired admiral said that he thinks Trump's stated commitment to NATO and the signing of the declaration shows the alliance is holding together — for now.

"I think crisis averted as in an immediate crisis, but I think there's long-term structural, fundamental creaking of that transatlantic bridge. On one side, the United States and Canada. On the other side, twenty-seven European allies. You just feel it kind of creaking in the wake of the commentary from President Trump."

Watch Power & Politics' full interview with retired Admiral James Stavridis below.