The North American Aerospace Defense Command (NORAD) are holding their largest training exercise since the Cold War this week in Labrador.

The military base in Happy-Valley-Goose Bay is hosting the annual NORAD operation, which involves American and Canadian air force troops training together to defend the north in the face of possible threats.

During the event, air force pilots will respond to simulated flying scenarios and practice reacting to different scenarios under pressure.

Once airborne, they will face live flying situations that simulate threats that North America might face.

This is the first time that the "Vigilant Shield" exercise has been hosted in Labrador, with over 550 troops participating at 5 Wing Goose Bay.

Fighter jet in Goose Bay

Canadian and American air force pilots are practising how to react to different scenarios under pressure during NORAD exercises in Labrador. (CBC)

Lt.-Col. Mark Roberts says it took over a year to plan the exercises, and that 5 Wing's facilities and geography make it a valuable location for the training.

"When we're detecting, deterring and defending North American airspace, what you want to be able to do is project your forces," said Roberts.

"You want to be able to forward deploy forces from main operating bases and Goose Bay is one of those such locations that we have in Canada."