WASHINGTON The federal government released groups of illegal immigrants from custody across the country Monday as the White House made its case that impending budget cuts would hurt efforts to protect the border and enforce federal immigration laws.

Advocates reported “waves” of illegal immigrants being released from at least three detention centers in Texas, Florida and Louisiana.

U.S. Immigration Customs and Enforcement confirmed the release of some illegal immigrants Monday night but would not say how many or from which detention centers.

“In order to make the best use of our limited detention resources in the current fiscal climate and to manage our detention population under current congressionally mandated levels, ICE has directed field offices to review the detained population to ensure it is in line with available funding,” said ICE spokeswoman Gillian Christensen. “As a result of this review, a number of detained aliens have been released around the country and placed on an appropriate, more cost-effective form of supervised release.”

Christensen said ICE is continuing to prosecute their cases in immigration court and will seek their deportation.

“We’re getting reports from multiple detention centers in Texas, Florida and New Orleans where detainees who are low priority are being released en masse without bond,” Domenic Powell, a spokesman for the National Immigrant Youth Alliance, an immigration advocacy group, said Monday night.

The White House has warned of the across-the-board spending cuts scheduled to take place this week as part of a 2011 bipartisan deal to reduce the deficit by $1.2 trillion over the next decade. Homeland Security secretary Janet Napolitano said Monday that the cuts would be “disruptive and destructive” to national security.

“Immigration and Customs Enforcement, also part of DHS, will be forced to reduce detention and removal and would not be able to maintain the 34,000 detention beds as required by Congress,” Napolitano said. “It would also reduce our investigative activities in areas like human smuggling and commercial trade fraud.”

Napolitano said Customs and Border Patrol would have to force all of its employees to take unpaid time off, reduce overtime and eliminate positions. She said reduced hours would mean up to 5,000 fewer Border Patrol agents working at ports of entry.