Trump announces ‘flexible’ exceptions that spare Canada and Mexico his 25% steel and 10% aluminum tariffs. Despite warnings by allies that a trade war will increase prices for consumers worldwide, President Trump signed proclamations Thursday imposing tariffs of 25% on imported steel and 10% on aluminum and said they are designed to protect American industries. In statements from the White House, Trump said his plan does exempt Canada and Mexico, pending the outcome of ongoing trade negotiations, and allows other countries to apply for relief from the new duties. Ref. USAToday.