The measure, approved unanimously Monday by councillors in the city just south of San Diego, California, frees up funds to deal with the potential arrival of deportees.

The intended uses include hiring personnel and paying for shelters and legal services.

The aim is to ensure a “dignified treatment” for deported migrants, Tijuana Mayor Ismael Burgueno said.

The city of more than two million people is one of the main destinations on the Mexico-US border for migrants hoping to enter the US.

Tijuana is home to numerous shelters that host foreigners from across Latin America as well as further afield.

Trump, who repeatedly called the arrival of migrants an “invasion,” has promised to declare a national emergency at the border with Mexico after taking office on Jan 20 and to expel millions who lack residency papers.

The Mexican government announced in December that it would launch a mobile app with an alert button for migrants facing imminent detention in the US.

The app, which foreign minister Juan Ramon de la Fuente said was expected to be ready this month, will also notify the person’s family.

There were an estimated four million unauthorized Mexican immigrants in the US in 2022, according to the US-based Pew Research Center.