President Trump on Saturday threatened Canada with steep tariffs if it “makes a deal with China” and insulted Prime Minister Mark Carney, his latest swing at the country since Mr. Carney pushed back against his policies in a highly publicized speech in Davos, Switzerland, this week.

“If Governor Carney thinks he is going to make Canada a ‘Drop Off Port’ for China to send goods and products into the United States, he is sorely mistaken. China will eat Canada alive, completely devour it, including the destruction of their businesses, social fabric, and general way of life,” Mr. Trump said in a post on Truth Social. “If Canada makes a deal with China, it will immediately be hit with a 100% Tariff against all Canadian goods and products coming into the U.S.A.”

There is no indication that Canada and China are in discussions about a broad trade agreement. Mr. Trump may have been reacting to Mr. Carney’s official visit to China last week, during which he agreed to lower tariffs on some Chinese electric vehicles in exchange for China doing the same for some Canadian agricultural products. The closely watched visit was billed as a crucial reset in the two countries’ relationship, but the trade agreement itself was modest.

Canada gave Jamieson Greer, the U.S. Trade Representative, a detailed preview of the agreement with China before it was signed, a senior Canadian official said, speaking on condition of anonymity to divulge details about communication between the two administrations. Mr. Trump appeared to praise Mr. Carney after the deal was announced. (“Good for him,” he said.)

But he soured on the prime minister after Mr. Carney’s Davos speech, in which Mr. Carney declared that the U.S.-led world order had been ruptured and called on “middle powers” like Canada to band together to survive a new and perilous era.

Without mentioning Mr. Trump or the United States by name, Mr. Carney pointedly called out the use of tariffs as coercion. “More recently, great powers have begun using economic integration as weapons, tariffs as leverage, financial infrastructure as coercion, supply chains as vulnerabilities to be exploited,” Mr. Carney said.