The Obama administration asked an appeals court on Friday to block the enforcement of Alabama's strict immigration law -- widely considered to be the toughest in the nation -- arguing it invites discrimination against foreign-born citizens and legal immigrants and is at odds with federal policy.
The Justice Department filed the challenge to the 11th Circuit Court of Appeals in Atlanta. It claimed Alabama's new law "is highly likely to expose persons lawfully in the United States, including school children, to new difficulties in routine dealings."
The overhaul allows authorities to question people suspected of being in the country illegally and hold them without bond. It also lets officials check the immigration status of students in public schools.
A federal judge in Alabama upheld those two key aspects of the law, which have already taken effect.
Those provisions that took effect are what help make the Alabama law stricter than similar laws passed in Arizona, Utah, Indiana and Georgia. Other federal judges have blocked all or parts of the laws in those states.
White House Press Secretary Jay Carney said Friday that President Obama has been clear on his position that "efforts to address the issue of America's broken immigration system through a patchwork of state laws will only create more problems than it solves."
Alabama shrugged off the appeal.
"The fact that the Department of Justice has appealed comes as no surprise," Alabama Gov. Robert Bentley said. "I remain committed to seeing that this law is fully implemented. We will continue to defend this law against any and all challenges."
Immigration became a hot issue in Alabama over the past decade as the state's Hispanic population grew by 145 percent to about 185,600. While the group still represents only about 4 percent of the population, some counties in north Alabama have large Spanish-speaking communities and schools where most of the students are Hispanic.
The Justice Department's appeal said parts of the law conflict with federal rules, and that "attempts to drive aliens `off the grid' will only impede the removal process established by federal law." It also said the legislation could impact diplomatic relations with foreign countries.
"Alabama is not in a position to answer to other nations for the consequences of its policy," it said. "That is the responsibility of the federal government, which speaks for all the states and must ensure that the consequences of one state's foray in to the realm of immigration law are not visited upon the nation as a whole."
It also said requiring officers to report people without adequate credentials to federal immigration officials "unnecessarily diverts resources from federal enforcement priorities and precludes state and local officials from working in true cooperation with federal officials."
The Associated Press contributed to this report.