Canada is moving ahead with the purchase of new submarines to replace its aging fleet, as it faces mounting pressure at this year’s NATO summit to spend more on the military.

Defence Minister Bill Blair made the announcement Wednesday, as NATO leaders, including Prime Minister Justin Trudeau, gather in Washington for the annual meeting of the alliance, which is marking its 75th anniversary.

Blair said the Canadian Navy is “taking the first step towards the procurement of up to 12″ subs to “covertly detect and deter maritime threats” but provided no details about the cost or timeline, only saying that the request will go out to the industry this fall to look at available options.

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For years, defence experts have urged the federal government to buy new subs to operate more effectively in the Arctic and defend Canadian sovereignty against increasingly aggressive behaviour from Russia and China.

“It’s long overdue. I would argue that this is a significant capability that should have been on the approved list, at least a decade ago,” said former navy Commander Retired Vice-Admiral Mark Norman in an interview with Global News.

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The Canadian navy has four 1980’s era diesel-powered submarines, but only one is operational.

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The new subs will have under-ice capabilities to counter “emerging security threats,” the defence minister said.

The fleet will need to “ensure that Canada can detect, track, deter and, if necessary, defeat adversaries in all three of Canada’s oceans,” added Blair.

The government is planning to buy conventional submarines, not nuclear ones like the U.S., Australia, and the U.K. do in their AUKUS defence pact; an alliance meant to counter China’s growing presence in the Indo-Pacific.

But Norman says Canada’s new fleet will likely be “high technology” and a welcome announcement for its military partners.

“It will all help demonstrate to our allies that we are taking our defence commitments seriously,” he said.

Canada routinely misses NATO’s target for members to spend two per cent of GDP on defence, and sources have told Global News the Biden administration is losing patience.

However, Norman warns the process could take years to acquire new submarines.

I’m very concerned about how long it takes us to do these types of things. Our track record is atrocious,” said Norman.

With files from Mercedes Stephenson, Sean Boynton, Marc-Andre Cossette