FBI director Robert Mueller warned Tuesday that the sharp budget cuts affecting all US agencies, including the federal police force, threaten crucial counter-terrorist operations.
The FBI boss, speaking before a House of Representatives committee, said that the $550 million in cuts over the next seven months until the end of the fiscal year will mean, among other things, leaving 2,200 vacant positions unfilled.
"The personnel are our resources, they are the FBI," he told lawmakers.
"Without them, we risk a slippage in ongoing operations and investigations that could undermine national security, and the enforcement of the federal criminal statues."
"Any furloughs would pose a risk to FBI operations in particular in the areas of counterterrorism and cyber," Mueller added.
"And currently we are exhausting all other options first in an effort to reduce any potential furloughs for our workforce," this year and next.
The so-called sequester is "going to hurt tremendously," he emphasized.
The large across-the-board spending cuts, known as the sequester, began on March 1.
A result of the political deadlock between Democrats and Republicans over budget plans to reduce the deficit, the sequester cuts will slash $85 billion in spending over the next seven months of fiscal 2013.