Spokeswoman Gillian Christensen said Wednesday that the agency "is committed to addressing the issues identified in the report and has already begun developing plans of action."
Citing internal budget documents, The Associated Press reported on March 1, 2013, that the administration had released more than 2,000 immigrants in the preceding two weeks and planned to release 3,000 more amid the looming budget cuts.
The White House and the Homeland Security Department disputed AP's reporting until March 14, when the then-ICE director, John Morton, acknowledged to Congress during a hearing that the agency had released 2,228 people from immigration jails, starting that Feb. 9, for what he described as "solely budgetary reasons."
At the time, Morton told lawmakers that the decision to release the immigrants was not discussed in advance with political appointees, including White House officials and Homeland Security Secretary Janet Napolitano.
He said the pending automatic cuts known as sequestration were "driving in the background."
The inspector general, John Roth, confirmed Morton's explanation, concluding that senior ICE officials did not inform Napolitano or the White House about the implications of the agency's budget shortfall and did not notify Napolitano about their plans to release the immigrants. Napolitano said days after the AP published its story that the report was "not really accurate" and that it had developed "its own mythology."
It was not immediately clear why Napolitano did not correct her statements about the accuracy of AP's reporting between March 1 and two weeks later, when Morton acknowledged the releases.
Republican Sens. Tom Coburn of Oklahoma and John McCain of Arizona asked the inspector general to investigate the decision to release the immigrants. Roth said that because the releases had occurred the weekend before new budget restrictions were put in place, they generated speculation that the releases were improperly motivated.
The 2013 releases drew sharp criticism from Republican lawmakers, who have said the administration has not done enough to address border security and was not properly enforcing immigration law.
Data published by the government in May 2014 revealed that the Homeland Security Department released 36,007 convicted criminal immigrants in 2013 who are facing deportation. That total includes those accounting for 193 homicide and 426 sexual assault convictions. The immigrants nearly all still face deportation and are required to check in with immigration authorities while their deportation cases are pending.
In his report, Roth concluded that ICE officials didn't anticipate the consequences of the 2013 budget-related releases and were unprepared to answer questions from Congress or the media.
Roth's report notes that ICE officials who released immigrants "made reasonable decisions given the short time frame."