President Trump railed against Canada on Tuesday, again accusing our northern neighbor of unfair trading practices — and a story in The Post that said Canadians come to the US to buy shoes and then smuggle them back into their country to avoid stiff tariffs.

“There was a story two days ago in a major newspaper talking about people living in Canada coming into the United States and smuggling things back into Canada because the tariffs are so massive,” he said during a rambling speech at the National Federation of Independent Business’ 75th anniversary celebration at the Hyatt Regency.

“The tariffs to get common items back into Canada are so high that they have to smuggle them in. They buy shoes, then they wear them. They scuff them up. They make them sound old or look old so they can get them past border guards.”

Post reporter Isabel Vincent, a native of Canada, had written a story in Sunday’s paper expressing her skepticism that Canadians would boycott American goods — and cited her, her family’s and her friends’ experiences buying lower-cost shoes, clothing and other items and sneaking them back across the border to avoid tariffs.

He also had some praise for the longtime US ally.

“They fought World War II with us. We appreciate it. They fought World War I with us, and we appreciate it, but we’re protecting each other,” he said before lashing out at NAFTA and Canadian tariffs on US dairy products.

“We’re treated horribly. Dairy. Dairy. 275 percent tariff. So basically that’s a barrier without saying it’s a barrier. We have to change our ways. We can no longer be the stupid country. We want to be the smart country,” he said to cheers and applause.

“So hopefully we’ll be able to work it out with Canada.”