In April 2017 the U.S. imposed duties averaging about 20 per cent on most Canadian softwood exports, alleging that Canada was both unfairly subsidizing its industry and then dumping wood into the U.S. at unfair prices.

The Trump administration says its tariffs imposed two years ago on more than $200 billion in Chinese goods were justified.

The decision comes after an agreement between the governments of Canada and Australia.

Trump and his top trade negotiator, Robert Lighthizer, are especially vociferous critics of the WTO. They argue that the trade organization constrains America's ability to counter unfair trading practices by China and other countries.

By taxing imported steel, Trump risked raising costs for the many U.S. industries that use steel, straining ties with American allies and defying the limits of his authority to unilaterally punish trading partners.

The IMF, in an updated economic outlook, projected the global economy would expand by 3% this year, the weakest in a decade.

Green Leader Elizabeth May argued that current agreements favour the rights of corporations at the expense of environmental protections.

The WTO's Appellate Body is down to three members from its normal seven, and U.S. has been blocking new appointments in an effort to force reforms.

Canada's trade minister is endorsing a European Union plan to prevent the Trump administration from paralyzing the World Trade Organization's dispute-settlement body later this year.

Despite few avenues for protection from the government, one former Canadian ambassador to Cuba says businesses there have tried to become "self-inoculated" from the lawsuit risk.