WASHINGTON - The US Commerce Department has affirmed findings that Canadian softwood lumber producers had unfairly subsidized and dumped product on the US market, saying efforts to negotiate a resolution had failed.

The development in the long-running trade dispute followed last month's apparent deadlock in trilateral talks to renegotiate the North American Free Trade Agreement, in which Canadian, US and Mexican officials have traded accusations of intransigence. "While I am disappointed that a negotiated agreement could not be made between domestic and Canadian softwood producers, the United States is committed to free, fair and reciprocal trade with Canada," Commerce Secretary Wilbur Ross said in a statement.

"This decision is based on a full and unbiased review of the facts in an open and transparent process that defends American workers and businesses from unfair trade practices." The United States imported $5.7 billion worth of Canadian softwood lumber in 2016, according to the department, up from $4.5 billion in 2015. US President Donald Trump's administration has defined itself in large part through an aggressive stance on trade, pledging to shift away from multilateral agreements while reducing trade deficits through countermeasures and bargaining.

Thursday's announcement followed August's move to launch a dumping probe into Canadian paper imports, which was followed by Washington's decision to impose heavy tariffs on imports of jets from Canadian aircraft manufacturer Bombardier. American officials have demanded access to Canada's protected dairy market, among other NAFTA talking points.

The Commerce Department said Thursday it had finalized determinations that Canadian exporters of softwood lumber had sold their product in the United States at between 3.2 percent and 8.9 percent below fair value. The department also believes Canada had unfairly subsidized the lumber exports at between 3.3 percent and 18.2 percent. US Customs and Border Protection has been ordered to collect cash deposits from importers based on these rates. The decision affirmed a preliminary action taken by the Commerce Department in April. The International Trade Commission, a separate body, is due to make its own final determination in the case next month.