WASHINGTON — Citing harm to U.S. farmers, President Donald Trump on Dec. 2 announced tariffs will be reimposed on all steel and aluminum shipped to the United States from Brazil and Argentina.

“Brazil and Argentina have been presiding over a massive devaluation of their currencies, which is not good for our farmers,” Mr. Trump said in a tweet. “Therefore, effective immediately, I will restore the tariffs on all steel and aluminum that is shipped into the U.S. from those countries.”

Brazil has been a leading exporter of steel to the United States, second only to Canada. The announcement came on the eve of a potential deadline for completion of the current round of trade negotiations between the United States and China. The next basket of tariffs targeting China is slated to come into effect Dec. 15 and would impact about $160 billion in Chinese goods. 

Argentina and Brazil have been beneficiaries of the U.S.-China trade war, capturing a larger share of China’s soybean and soy product imports.