“There is no reason, rationale or justification to support this decision that will affect our people and nations … Nobody wins with this decision,” Sheinbaum said at her regular morning press conference.

Trump’s tariff actions went live at 12:01 a.m. in Washington (0501 GMT) after an initial 30-day pause, during which Mexican officials engaged in talks with Washington and bolstered security at the US-Mexico border.

Trump on Monday declared that Mexico, along with Canada and China, had failed to do enough to stem the flow of the deadly opioid fentanyl and its precursor chemicals into the US.

Sheinbaum said Mexico had collaborated with the US on migration, security and anti-drug trafficking.

“In these 30 days, decisive actions were taken against organized crime and fentanyl trafficking, as well as bilateral meetings on security and trade,” Sheinbaum said.

Sheinbaum said she would give details on Mexico’s response, including retaliatory tariffs, at an event in the capital’s iconic Zocalo square on Sunday.

The Mexican peso weakened on Tuesday morning, trading down around 1% against the dollar.