Concerns about the policies to be pursued by the incoming Trump administration have caused a freeze on new investment in maquiladoras on the Mexican side of the border, where thousands of workers in that industry face an uncertain future.

Case in point is Ciudad Juarez, a city across from El Paso, Texas, where the first of the maquiladoras - plants where goods are assembled for export - was installed in 1968 and the maquila industry accounts for more than 60 percent of the local economy.

"The current situation is one of uncertainty, of doubt about what (President-elect Donald) Trump may do," said Manuel Ochoa, vice president of business development for the Tecma Group, a provider of shelter services to facilitate the setting-up of maquiladoras in Mexico by foreign manufacturers.

Trump, who takes office on Friday, has said he will impose tariffs of up to 35 percent on US companies who move operations to Mexico with the idea of selling their products back to the American market.

"The current situation is one of uncertainty, of doubt about what Trump may do," said Manuel Ochoa, vice president of Tecma Group, a provider of maquiladoras in Mexico by foreign manufacturers.

That would mark an abrupt shift away from the current climate of virtually tariff-free US-Mexico trade for qualifying goods under the North American Free Trade Agreement (NAFTA), which the president-elect says must be renegotiated.

Inside the maquiladoras, conversations among workers reflect their fear of being laid off in the near future.

"The bosses haven't told us anything, but there's been talk that the maquila could close and they're going to throw us out on the street," Mary, a worker at a factory with US capital in Ciudad Juarez, told EFE.

At present, the more than 320 maquiladoras installed there employ some 250,000 men and women, a sixth of the city's total population.

Amid pressure by Trump, Ford made a surprise announcement early this year that it would cancel plans for a $1.6 billion plant in the north-central state of San Luis Potosi and instead invest that money in Michigan, a move seen in Ciudad Juarez as a bad omen.

But Hector Nuñez Polando, director of the Economic Development of the North Civil Association, sounded a note of optimism.

"The main impact would be on new (investment), on growth; it's very difficult to remove what's already been established," Nuñez said.