Winnipeg's mayor is wading into the burgeoning aerospace trade war centred around Boeing and Bombardier.

Brian Bowman says Winnipeg -- home to a Boeing manufacturing facility that employs 1,400 people -- is the largest aerospace centre in Western Canada and is the third biggest in the country.

He says cooler heads need to prevail so the sector can continue to grow.

Quebec Premier Philippe Couillard has called on Ottawa to take a hard line against Boeing after the U.S. Department of Commerce proposed a hefty 219 per cent duty on jets manufactured by rival Bombardier.

Couillard said "not a bolt" made by Boeing should enter Canada until the conflict is resolved.

Bowman says Couillard's comments are an oversimplification and Canada must keep its borders open to trade.