The US authorities have started flying illegal Mexican immigrants back to their country under a controversial new repatriation programme.
The US is planning to run daily repatriation flights to Mexico
On Tuesday about 130 people arrived in Mexico City on the first flight.
They had agreed to be flown from Tucson, Arizona, rather than be deported across the border, as part of a new project run by the two countries.
Each day thousands of Mexicans enter the US on foot via the Arizona desert in the hope of finding work.
US officials say the aim of the programme is to save lives by helping migrants from Mexico's interior return to their communities, instead of attempting repeated and dangerous crossings.
Last year an estimated 139 died, falling prey to the heat, bandits or vigilantes.
The repatriation initiative is scheduled to run until the end of September, with two flights a day to Mexico City and Guadalajara.
US border patrol spokesman Andy Adane told Reuters news agency that many of the 1,200 migrants captured daily on the US side become trapped in Mexican border towns with no money to return home.
The programme, he said, was giving migrants "the opportunity to live and return home safely".
But an Arizona-based immigrants rights group dismissed the idea that the repatriations were designed to benefit Mexicans.
"People aren't staying in (Mexican) border communities because they can't get home - they are staying because getting across the border is their mission," said Jennifer Allen, director of Border Action Network.
Those deported on Tuesday do appear to view their repatriation as a temporary move.
Most told AP news agency that they intend to see their families, have a rest, and then head north again.
"There is no work here," 22-year-old Martin Islas told AP.
After their arrival in Mexico City, migrants were taken to bus terminals from where they were expected to travel on to communities across the country.