NEW YORK/OTTAWA - Trade tensions between the United States and Canada escalated Tuesday as US President Donald Trump announced new import bans and tariff adjustments on Canadian products.

Trump signed five proclamations under Section 338 of the Tariff Act of 1930, banning imports of certain Canadian alcoholic beverages, dairy and other products previously subject to 50-percent tariffs. The import bans will take effect on Sept 29.

The measures also revise the scope of tariffs announced on July 20, removing products including rock salt and cement while adding others such as all-terrain vehicles and additional dairy products. The changes will take effect on Sept. 15.

The Section 338 tariffs apply to covered Canadian goods regardless of whether they qualify for preferential treatment under the US-Mexico-Canada Agreement, and are imposed in addition to tariffs under Section 232 of the Trade Expansion Act of 1962.

Earlier Tuesday, Trump also directed the US Trade Representative and the General Services Administration (GSA) to remove 50 billion US dollars worth of Canadian-origin products from the GSA's Multiple Award Schedules.