A US administration official, who reviewed the decision before it was announced, said that Canada was among the few countries, along with China, that responded with retaliatory measures to the previous tariffs imposed by Trump, stressing that it must be held accountable for that, according to the Associated Press.

He explained that Trump signed three presidential proclamations to impose duties under Section 338 of the Trade Act of 1930. A number of Democratic lawmakers had proposed last year to abolish this article, considering that Trump might use it to destabilize the economy.

The 50 percent tariff will exclude energy products, potash, fish and critical minerals, but will include goods that previously enjoyed an exemption from import duties under the United States-Mexico-Canada trade agreement.

This agreement, which entered into force in 2020, recently expired, launching a new round of negotiations that may continue until 2036.

The official added that Trump also asked his aides to study imposing additional customs duties on Canada, considering that its forest fires negatively affected air quality in the United States.

The White House said, in a fact sheet, that the tariffs will take effect within 30 days, allowing room for negotiations, as Trump did not always implement all of the increases he previously announced on import duties.