Mexico has hit back fast on US tariffs on steel and aluminium, targeting products from congressional districts that President Donald Trump's Republican party is fighting to retain in November elections.
Economy Minister Ildefonso Guajardo says the tit-for-tat measures will complicate talks between the US, Canada and Mexico to revamp the North American Free Trade Agreement (NAFTA) that underpins trade between the neighbours.
The spat means it will be "very difficult" to reach a deal to revamp NAFTA before Mexico's July 1 presidential election, though he has underlined the continent had not entered a trade war.
"A trade war is when there is an escalation of conflict. In this case, it is simply a response to a first action," Guajardo told Mexican radio on Thursday.
Mexico's retaliatory tariffs target pork legs, apples, grapes and cheeses as well as steel - products from US heartland states that supported Trump in the 2016 election.
The country reacted right after Washington said it was moving ahead with tariffs on aluminium and steel imports from Canada, Mexico and the European Union.
"It sends a clear message that this kind of thing does not benefit anybody," Guajardo said of the Mexican retaliation.
Mexico said it was imposing "equivalent" tariffs, ratcheting up tensions during talks to renegotiate NAFTA before the US midterm elections in November.
The measures would be in place until the US government drops its tariffs, Mexico's government said.
"It is a sad day for international trade," Guajardo said.
"But hey, the decision was made, and we always said that we were going to be ready to react."
Canadian Prime Minister Justin Trudeau and Mexican President Enrique Pena Nieto spoke by phone after the US announcement.
Canada pledged to fight back with its own measures.