The Department of Homeland Security has started releasing hundreds of illegal immigrants held in local jails in anticipation of automatic budget cuts, in a move one Arizona sheriff called politically motivated -- and dangerous.

Pinal County Sheriff Paul Babeu said Tuesday that Immigration and Customs Enforcement released more than 500 detainees in his county alone over the weekend. A spokesman for Babeu told FoxNews.com that ICE officials have said they plan to release a total of nearly 10,000 illegal immigrants.

The numbers, though, are in dispute. ICE officials said that it's unclear how many ultimately might be released and that only 303 have been released from four Arizona facilities so far, though all those are in Pinal County. According to ICE, 2,280 detainees are still in custody in those facilities.

Babeu described the move as a "mass budget pardon" and suggested the administration was going to unnecessary lengths to demonstrate the impact of the so-called sequester.

"President Obama would never release 500 criminal illegals to the streets of his hometown, yet he has no problem with releasing them in Arizona. The safety of the public is threatened and the rule of law discarded as a political tactic in this sequester battle," he said.

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An ICE spokeswoman confirmed the plans without specifying how many illegal immigrants might be released.

Spokeswoman Gillian Christensen said ICE had directed field offices to make sure the "detained population" is "in line with available funding." She stressed that ICE would continue to prosecute the cases while keeping them under supervision.

"Over the last week, ICE has reviewed several hundred cases and placed these individuals on methods of supervision less costly than detention," she said. "All of these individuals remain in removal proceedings. Priority for detention remains on serious criminal offenders and other individuals who pose a significant threat to public safety."

The announcement comes after DHS Secretary Janet Napolitano on Monday warned about the potential impact of the cuts. She said the department "would not be able to maintain the 34,000 detention beds as required by Congress."

"We're doing our very best to minimize the impacts of sequester. But there's only so much I can do," she said. "I'm supposed to have 34,000 detention beds for immigration. How do I pay for those?"

Republicans in Congress, though, have challenged the numerous Obama Cabinet secretaries warning about the devastating impact to their departments. With cuts set to take effect Friday and no deal in sight to avert them, Republicans claim the administration is trying to make the cuts seem worse than they are -- some want to give the administration more leeway so that high-priority agencies don't get hit as hard.

House Judiciary Committee Chairman Bob Goodlatte, R-Va., called the move to release illegal immigrants "abhorrent." "By releasing criminal immigrants onto the streets, the administration is needlessly endangering American lives," he said in a statement.

Sen. Jeff Sessions, R-Ala., also said "these savings could be much more safely and rationally achieved."

In Arizona, Babeu slammed the move, painting his community as a victim of gridlock in Washington.

"Clearly, serious criminals are being released to the streets of our local communities by this mass budget pardon. These are illegals that even President Obama wants to deport. This is insane that public safety is sacrificed when it should be the budget priority that's safeguarded," he said.