Opposition to Obama's migration plan
US President Barack Obama is expected to appeal the order of Texas judge, which would suspend immigration enforcement measures announced in November.
The measure seeks to regularize the status of more than five million undocumented immigrants.
The judge's decision fell just before the start of the registration period for which thousands of young undocumented immigrants, many of them Mexicans and Central Americans might be eligible for deferred action.
A deferral can last for three years and includes a temporary work permit.
Obama's plan, scheduled to begin in May, also includes a program that would grant work permits to parents of US citizens or children with permanent status.
The judge's decision responds to a demand by a coalition of 26 states, which say that the President exceeded his powers.