Canada has vowed to match new US tariffs “dollar for dollar” after trade talks between the two countries collapsed, according to the BBC and Sky News. The United States has imposed a 50% tariff on $20bn (£14.6bn) worth of Canadian goods, a levy that came into force following what the BBC described as a last-minute breakdown in negotiations.

Canadian Prime Minister Mark Carney announced the retaliatory measure, saying his country would respond in kind to the new American duties. “Last-minute changes in the US proposed terms were unfair, uneconomic, and called into question the reliability of any deal,” Carney said in a statement reported by the Guardian.

The two sides had been working toward a trade agreement but failed to reach one by a midnight deadline, even after a three-day extension of talks, according to the Guardian. The failure to strike a deal triggered the new tariffs and Canada’s promise of matching measures.

The dispute marks a sharp turn between the two long-standing allies. Sky News noted that Canada has vowed to retaliate against what it called its historic ally, framing the confrontation as a significant rupture in the relationship between the neighbouring economies.

Carney reiterated the retaliatory stance in comments carried by Al Jazeera, again stating that Canada would match the US tariffs “dollar for dollar.” The scale and specific targets of Canada’s countermeasures were not detailed in the available reporting.

The new levy affects $20bn of Canadian imports at a rate of 50%, according to Sky News and the BBC. The reporting did not specify which categories of goods are covered by the tariffs or when Canada’s matching measures would take effect.