Budget cuts due to take effect in March - unless blocked by Congress - would "hollow" the US military's ability to respond to threats, Defence Secretary Leon Panetta warned Thursday, dpa reported.
"We would be forced to do what I said we should not do with the defence budget, which is to hollow out the defense force of this nation," he said, pointing to automatic cuts left unresolved during an agreement last week to avert the austerity measures known as the fiscal cliff.
Congress reached agreement on taxes but postponed until March severe spending cuts that observers warn would devastate government programmes.
Panetta said total cuts of up to 20 per cent to the Defence Department's operating budget would have severe impacts on training, maintenance and other priorities, even as he vowed not to reduce spending on troops in Afghanistan and wounded soldiers.
Panetta said he had already asked the military and civilian employees to draft plans for how they would deal with the cuts.
The cuts come alongside discussion over increasing the US debt limit and the lack of a full 2013 budget, creating a "perfect storm of budget uncertainty," he said.
He called on Congress to take action, sounding the alarm about the severity of the impact as a "very serious threat to our national security."
"I really do understand how difficult the politics are on Capitol Hill to confront and try to resolve this very serious fiscal crisis that this country is in," said Panneta, a former congressman who headed the House budget committee. "But all of us in Washington - all of us in Washington have a responsibility to the American people to provide for our national security and to keep them safe."