The Department of Homeland Security says deportations will begin this week for the illegal immigrants, many of them children, pouring over the border.
Most of them will eventually be sent home.
In the last nine months, more than 57,000 people have crossed the border, and another 30,000 are believed on the way from several central American countries.
The government is trying to deal with a looming humanitarian crisis, while sending the message that undocumented aliens are not welcome.
The President has asked for three point seven billion dollars to deal with the immediate crisis.
But House Republicans refuse to fund a short term fix without long term immigration reform.
Senator John McCain says Central American parents will only stop sending their children to the U.S. if they see they are wasting their money when the children are sent back.
Republicans are hoping to pass a new border security bill before next month.