An X post reported, "Here’s the key issue: Canada was bringing in Chinese steel and aluminum and selling it as Canadian steel to help China avoid tariffs. When told to knock it off, they refused. This is why the trade deal collapsed. We cannot allow China to build a proxy state on our border."

U.S. businesses and the U.S. government have accused Canadian companies of acting as a "backdoor" funneling Chinese steel into the United States. President Donald Trump's administration also has accused Canada of being one of China's "biggest enablers" in efforts to avoid tariffs in general.

Economist Justin Wolfers said Canada’s retaliatory tariffs carry limited short-term economic weight but could inflict political pain on President Donald Trump because Ottawa targeted products concentrated in politically sensitive states.

The US and Canada should stop targeting each other with aluminum tariffs, according to industry groups representing producers of the metal in both countries, and instead forge a common front against Chinese competition.

President Donald Trump threatened to ban Bombardier aircraft sales on Truth Social just hours before Canada's retaliatory tariffs hit $20 billion in U.S. goods.

New U.S.-Canada tariffs hit some brands hard and skip most. The difference isn't your company's flag, it's where your goods are made and which border they cross.

Trump suggests he could expand the U.S.-Canada trade conflict as Ottawa’s retaliatory tariffs come into effect.

U.S. President Donald Trump’s trade war with Canada is getting personal for American farmers. After trade talks between the two longtime allies fell apart

Canada struck back at U.S. President Donald Trump on Tuesday with tariffs on about $20 billion worth of U.S. goods, in response to his latest round of tariffs on Canada