Canada is seeking an exemption to new U.S. trade restrictions on aluminum and steel, and is vowing to retaliate if it's slapped with any new tariffs.

Prime Minister Justin Trudeau called the proposal "absolutely unacceptable," echoing the phrase used by Foreign Affairs Minister Chrystia Freeland yesterday.

A government official, speaking on background, said Canada believes any new tariffs should not apply to this country due to the highly integrated nature of the North American steel market, and because of the close co-operation between the two countries on defence issues.

This was excerpted from the 2 March 2018 edition of CBC News.