Washington, Sept. 9 -- The United States has announced a fresh round of trade measures against Canada, banning several categories of imports and reshuffling existing tariffs after Ottawa imposed its own retaliatory tariffs on American goods.

Speaking to reporters on a background call, a senior US official said President Donald Trump had signed a series of proclamations under Section 338 of the Tariff Act of 1930, a rarely used law that lets Washington ban imports from countries it says are treating US trade unfairly.

The measures move on three fronts. Canadian dairy products, most alcoholic beverages and motorcycles will now be barred from entering the US, with the bans due to take effect in roughly three weeks. Alongside this, Washingt...