Lt.-Gen. Michael Hood also says Canada's allies are developing ways to upgrade the aging aircraft to reduce the risks and costs if they are needed for even longer periods of time.

More than 200 federal civil servants involved in replacing Canada's aging fighter jet fleet have been forced to swear they will not discuss the project for the rest of their lives.

The government says it plans to discuss the issue with the U.S. and Boeing to determine whether Super Hornets can be procured "at a cost, time, level of capability and economic value that is acceptable to Canada."