OTTAWA, Aug. 23 (Xinhua) -- Canada will impose "dollar-for-dollar" tariffs on about 20 billion U.S. dollars' worth of American goods from Sept. 8 in retaliation for Washington's latest duties, Prime Minister Mark Carney said Saturday.

The 50-percent U.S. tariffs, covering an equivalent value of Canadian goods, took effect just after midnight Saturday following the collapse of trade talks on Friday, further straining relations between the longtime allies.

LAST-MINUTE BREAKDOWN

Carney said he suspended the talks because Washington introduced last-minute changes that were "unfair, uneconomic, and called into question the reliability of any deal," even though the two sides had appeared close to a mutually beneficial agreement earlier in the week.

U.S. President Donald Trump signed three proclamations on July 20 to impose additional 50-percent tariffs on certain goods from Canada, citing Ottawa's "discriminatory treatment of American products."

On Tuesday, Trump announced a three-day pause of the tariffs, which were scheduled to take effect on Wednesday, saying the two sides had reached a deal pending the finalization of formal documents.

Carney said on Saturday that Canada had been prepared to remove its remaining retaliatory tariffs on U.S. steel, aluminum and automobiles if Washington substantially reduced its corresponding duties, and was also willing to encourage Canadian provinces to return U.S. alcoholic beverages to store shelves.

"They asked too much and offered too little," he said.

According to Carney, the U.S. proposals restricted Canada's ability to pursue trade arrangements with other countries, and undermined its protections for the French language, culture and national sovereignty. He did not disclose the details of those demands.

Washington, however, blamed the breakdown largely on late demands from Canada, with U.S. tariff rates on heavy-duty trucks emerging as a key sticking point, Politico reported, citing people familiar with the talks.

"They've always had the best deal, and they still would have an even better deal, but they didn't want that," U.S. Trade Representative Jamieson Greer told Fox News, adding that no further trade talks are scheduled with Canada.

A UNITED RESPONSE

In his televised address, Carney announced retaliatory tariffs targeting U.S. steel, dairy, appliances, agricultural equipment, pulp and paper, and electronics, and promised to release the details in the coming days.

"You're at war when you're attacked, and we got attacked," Carney said when asked whether Canada was in a trade war with the United States.

Carney's tough position has drawn broad support across party and provincial lines.

Pierre Poilievre, leader of the main opposition Conservative Party, called on Canadians to stay united against "unfair attacks."

"Canada cannot accept one-sided tariffs that will deindustrialize our country. Nor can we accept a bad deal," he said.

Several provincial premiers also backed Carney's decision.

Ontario Premier Doug Ford said the prime minister had his "full support" for a strong response "tariff for tariff, dollar for dollar," urging provincial leaders to remain united as "Team Canada."

British Columbia Premier David Eby noted that U.S. demands that Canada cut or reduce its trade with other countries would turn it into "the economic equivalent of the 51st state," which he described as "never acceptable" to Canadians.

Saskatchewan Premier Scott Moe said in a statement that while the U.S. tariffs will hurt, Carney made the right decision to reject an "unfair and unreliable" deal.

A recent Leger poll found that 56 percent of Canadians wanted the government to take a hard line and make no further concessions in talks with the United States, and more than 70 percent supported stronger retaliatory trade measures.

A BROADER SHIFT IN ECONOMIC TIES

In his address, Carney argued that the decades-long expansion of economic integration between Canada and the United States was over.

He accused Washington of using economic integration as a weapon.

"We have recognized from the beginning that America has changed, and that we will not return to our old relationship," Carney said.

He also criticized the shifting U.S. justifications for tariffs, ranging from fentanyl and a television advertisement quoting former U.S. President Ronald Reagan to bridge tolls and wildfire smoke, as lacking seriousness and severely damaging foundational trust.

Since taking office in 2025, Carney's government has accelerated efforts to reduce Canada's economic dependence on the United States and diversify its trade relationships.

Ottawa has sought to expand trade with markets in Europe and Asia, develop ports and energy corridors, remove internal trade barriers and double Canadian exports to non-U.S. markets over the next decade, Carney said in his address.

The collapse of talks has also added uncertainty to the future of the U.S.-Mexico-Canada Agreement. The pact remains in force, but the latest U.S. tariffs apply even to Canadian goods that comply with its rules, unlike many earlier U.S. duties.

The scope for a rapid shift, however, remains limited. The United States still accounts for roughly three-quarters of Canada's merchandise exports, while cross-border supply chains in sectors such as automobiles and energy remain deeply integrated.

Meanwhile, Carney underscored the importance of Canadian energy to the United States, noting that Canada supplies 99 percent of U.S. natural gas imports, 85 percent of its electricity imports and 60 percent of its crude oil imports.

"I don't think they want us to stop sending it," he said.