Defence Minister Harjit Sajjan's new marching orders from the prime minister put special emphasis on the expensive and politically touchy necessity of renewing Canada's commitment with the United States to defend the skies and sea lane approaches to North America.

The minister's mandate letter, signed by Prime Minister Justin Trudeau, was released Friday and also instructs Sajjan to sign a contract to acquire a fleet of new fighter jets within the Liberal government's current mandate — a process that's already underway.

But it is the plan to "modernize" the North American Aerospace Defence Command (NORAD) that will likely require the most political stick-handling for the minority government.

There is a necessity "to develop better surveillance (including by renewing the North Warning System), defence and rapid-response capabilities in the North and in the maritime and air approaches to Canada, to strengthen continental defence, protect Canada's rights and sovereignty and demonstrate international leadership with respect to the navigation of Arctic waters," the mandate letter said.

Modernizing NORAD, the 62-year-old binational defence pact, was one of the first items on the agenda in the first meeting between Trudeau and U.S. President Donald Trump in 2017.

Renewed NORAD

They agreed it was a priority, and the U.S. and Canadian militaries began scoping out the parameters. In August, CBC News reported that they had agreed on the "capabilities" that could go into a renewed NORAD.

Defence officials on both sides of the border still have to turn the notions into policy proposals with price tags, something that is ongoing.

There has been no formal political agreement.

Sajjan, at the time, shortly before the election, released a statement emphasizing that Canada and the U.S. had not struck a government-to-government agreement, which perhaps unintentionally underlined the political sensitivity of the subject.

NORAD renewal, including the replacement of the chain of radar stations known as the North Warning System, was not costed in the Liberal defence policy.

Ballistic missile defence?

Some experts conservatively estimate the revamp of the radar platforms will run both countries a combined bill of $11 billion — 40 per cent of which would be Canada's responsibility.

Also, the renewal of NORAD raises questions about whether Canada could, or should, join the U.S. ballistic missile defence system — a politically divisive subject that has lain dormant since 2005, when then-prime minister Paul Martin declined to take part.

Sajjan's mandate letter also commits him to "introduce a new framework governing how Canada gathers, manages and uses defence intelligence, as recommended by the National Security and Intelligence Committee of Parliamentarians."

That committee has been studying how military intelligence has operated for years without the same oversight checks and balances as the Canadian Security Intelligence Service.