Trump flaunts 'secret' migration deal already revealed by Mexico

Revealing more details of Mexico's strategy for rapidly putting the brakes on immigration, Ebrard said on Tuesday that border infrastructure on its southern frontier would be improved significantly. To meet its commitments to Washington, Mexican migration facilities in the south need to be revamped, he said.

"You go to the south and the first thing you ask yourself is 'Right, where's the border?' There's nothing. The idea is to make the south like the north as far as possible," he said.

Over the weekend there was no sign that Mexico had started to harden the border, with migrants and locals crossing a river on rafts in sight of a busy official port of entry.