Attorney General Eric H. Holder Jr. warned Tuesday that Americans will be less safe if federal agencies have to absorb the major cuts set to go into effect Friday under what's known as the sequester.

Speaking at a National Association of Attorneys General meeting in Washington, Holder said that furloughs of federal law enforcement agencies would try to minimize the effects of the budget cuts, but that "the reality is there is going to be harm." 

"It's going to have an impact on law enforcement," Holder said, including FBI, DEA and ATF officials.

Homeland Security Secretary Janet Napolitano reiterated her warnings from a day ago about the impact of sequestration on DHS enforcement capabilities in an address at the Brookings Institution.

"I have never seen anything like this," Napolitano said of the sequester in response to a questioner. "It will have to affect our core critical mission areas.... We are a department that is dependent on personnel. So when we add it up, it is the equivalent in hours of 5,000 Border Patrol agents. It means less overtime and ability to hire port officers."