Defence Secretary Chuck Hagel has unveiled plans to shrink the US Army to its smallest size since before World War Two.
Outlining his budget plan, the Pentagon chief proposed trimming the active-duty Army to 440,000-450,000 personnel, down from 520,000 currently.
Cold War-era Air Force fleets – the U-2 spy plane and the A-10 attack jet – will also be retired.
However, the plan requires approval from Congress, which could change it.
The US military is under pressure to downsize after two costly foreign wars.
Mr Hagel said at the Pentagon on Monday: “This is a time for reality.
“This is a budget that recognises the reality of the magnitude of our fiscal challenges.”
He added: “There are difficult decisions ahead. That is the reality we’re living with.”
The number of active-duty US Army members was already expected to be pared down to 490,000, as the US prepares to end its combat role in Afghanistan later this year.
Noting the current US Army strength, Mr Hagel added: “Since we are no longer sizing the force for prolonged stability operations, an Army of this size is larger than required to meet the demands of our defence strategy.”
Mr Hagel said the administration would also recommend closing some domestic military bases in 2017, though such proposals have been rejected by Congress in recent years.
The Pentagon chief went on to unveil plans for changes to pay and benefits.
He recommended curbing housing allowances, limiting pay raises and increasing healthcare premiums.
However, the military cost-cutting drive could well cause ructions on Capitol Hill, which is gearing up for November’s midterm elections.
Reaction to the proposal was swift, with Republican members warning such cuts could hurt military readiness.
“The world is not getting to be a safer place. This is not the time for us to begin to retreat, and certainly not the time to cut our military,” Republican Representative Michael Turner told Bloomberg News.
Representative Michael McCaul, chairman of the House Homeland Security Committee, blamed US President Barack Obama’s administration for the predicament, saying cuts were only necessary because they had not been made elsewhere.
“It’s all being sacrificed… on the altar of entitlements,” he told Fox News. “This president cannot take on mandatory spending, so all we’ve done in the Congress – and this president – is basically cut discretionary spending.”
The proposed Army staffing levels would be the lowest since 1940 – before the US entered World War Two – when 267,000 active-duty members were employed.
By the end of that conflict, there were 8.2 million active-duty US Army members, according to figures provided on Monday by the Pentagon.
The figure peaked at 1.6 million both during the Korean War, in 1952, and during the Vietnam War, in 1968.
The number was 482,000 in 2000, a year before the attacks of 11 September 2001.
After those attacks, the force peaked at 566,000 in 2010.