OTTAWA - The Harper government's Arctic policies don't come cheap.

A series of internal Defence Department documents show that the biggest concern isn't getting forces into the harsh region.

The annual cost of supplying them with fuel, ammunition, food and shelter could run between $843 million and $1 billion dollars.

The documents show the navy, air force and army have begun to grapple with the logistical challenges presented by the Arctic policies.

The reports dating back to 2008 suggest the military will have to look to commercial contractors and possible exchanges with the Americans in order to sustain itself.

Arctic expert Rob Huebert of the University of Calgary says Ottawa will have to be smart about how it implements its strategy.

The top military commander, General Walt Natynczyk, said recently that it's harder to sustain operations in the High Arctic than it is in Afghanistan.

The documents were obtained by The Canadian Press under access to information laws.