OTTAWA - A massive Russian polar exercise involving tens of thousands of troops plus ships, submarines and aircraft, is intended to tell the world that Moscow is still a global player, says the U.S. commander of North American air defence.

The training manoeuvre, one of the Kremlin's biggest shows of force since the end of the Cold War, brought the Russian navy's northern fleet to full combat status on Monday.

U.S. Admiral Bill Gortney, the commander of NORAD, met Defence Minister Jason Kenney on Monday and said the message from the exercise is clear, but what the Russians hope to accomplish beyond that remains a mystery.

"What I'm just never certain about is: What is their intent?" Gortney said in a conference call from Colorado Springs, Colo. "What is their intent beyond the messaging?"

The drill is being held just ahead of a large NATO Arctic exercise in Norway and as preparations are made to mark the first anniversary of the referendum which resulted in the annexation of Crimea by Russia.

For months, NORAD has been dealing with a rising number of incidents in which Russian warplanes test North American airspace boundaries and it's something Kenney says the federal government has "noted with interest."

The Kremlin announced in 2013 that it would permanently base two combat brigades in the Arctic, the first one of which began moving into its base near the Finnish border earlier this year.

Canada's defence plans in the Arctic were drawn up over seven years ago, and many of the promises, including icebreaking patrol ships and a deepwater port, have yet to be fulfilled.

"As you know, the government is considering a renewal of the Canada First Defence Strategy, in which we will consider the higher pace of activity in the Arctic," Kenney said. "It's hugely important for Canada to play a role."

Another part of the consideration is the "modernizing of NORAD's capacity to detect potential threats."

The Harper government has yet to say whether it is in favour of joining the U.S.-led ballistic missile defence program. If approved, it would reverse a decision made by a Liberal government a decade ago.

The Canadian Senate defence committee, with the backing of two former Liberal cabinet ministers, released a report last year that recommended Canada join the missile plan.

A House of Commons committee is conducting a parallel investigation, and Kenney says the government is waiting for MPs to weigh in before making up its mind.