At a news conference at Canada's largest air base in Trenton, Ontario, Minister Anita Anand outlined Can$4.9 billion (US$3.8 billion) in military spending over the next six years.

The monies are to be spent on land and satellite-based radar that can spot incoming bombers or missiles "over the horizon," as well as a network of sensors with "classified capabilities" to monitor Arctic air and sea approaches to the continent.

It is all part of a modernization of the North American Aerospace Defense Command (NORAD) and early warning systems, which has been stepped up following Russia's invasion of Ukraine in February.

The new systems will replace an aging Cold War-era North Warning System, whose almost 50 short- and long-range radar stations from Alaska to northern Quebec are incapable of responding to modern missile threats.

"As autocratic regimes threatened the rules-based international order that has protected us for decades, and as our competitors develop new technologies like hypersonic weapons and advanced cruise missiles, there is a pressing need to modernize Canada's NORAD capabilities," Anand said.

The new spending, she said, represents "the most significant upgrade to NORAD from a Canadian perspective in almost four decades" and will "push our line of sight further north, ensuring that we will be able to respond to fast-moving threats."

The United States has already budgeted new spending for continental defenses.

In March, Ottawa also unveiled plans to buy 88 US-made F-35 stealth fighter jets to replace its aging fleet. Their main role will be to patrol the far north.