Orange juice from Florida. Whiskey from Tennessee. Peanut butter from Kentucky.

Canada is preparing for an all-out trade war with its closest ally and one of its top trading partners, and the list of American goods that could be affected is long.

Canadian officials are preparing a three-stage plan of retaliatory tariffs and other trade restrictions against the United States, which will be put into motion if President-elect Donald J. Trump makes good on his threat to impose a blanket 25 percent tariff on all Canadian goods imported into the United States.

Canadian officials will wait until Mr. Trump has made his move — which he has said will be on his first day in office, Monday — and then start with imposing tariffs. They would mostly affect consumer goods worth 37 billion Canadian dollars ($25.6 billion), according to two senior government officials familiar with the plans.

They spoke on condition of anonymity to discuss details of plans meant to remain private for now.

Goal: Maximum political pain

The Canadian officials said their choice of goods was meant to be precisely targeted and aimed at political impact. They specifically want to focus on goods made in Republican or swing states, where the pain of tariffs, like pressure on jobs and the bottom lines of local businesses, would affect Trump allies.

Canada’s government hopes that those allies, including governors or members of Congress, would then pick up the phone and call Mr. Trump, intervening in favor of de-escalation.

Mélanie Joly, Canada’s foreign minister, who spent Thursday and Friday in Washington, met with a slew of Republicans to make her country’s case, including Senator Lindsey Graham of South Carolina, Senator Jim Risch of Idaho, and the Senate majority leader, John Thune of South Dakota.