US President Barack Obama has warned that looming budget cuts would damage the US military's readiness and urged for a deal to avoid the massive spending reductions.
"Let me say this: There is no reason - no reason - for that to happen," said Obama, referring to automatic budget cuts due to take effect by a March 1 deadline.
"Putting our fiscal house in order calls for a balanced approach, not massive, indiscriminate cuts that could have a severe impact on our military preparedness."
Obama delivered his appeal at Fort Myer, outside Washington, at a farewell ceremony for his outgoing defence secretary, Leon Panetta, who has repeatedly portrayed the potential cuts as "devastating" for the armed forces.
"So here today, for the sake of our prosperity, for the sake of all these men and women in uniform, and all their brothers and sisters in uniform that they represent, now's the time to act," Obama said.
It was time, he said, "for Democrats and Republicans to come together in the same spirit that Leon Panetta always brought to public service, solving problems, not trying to score points, doing right for the country, not for any particular political agenda."
If Congress fails to break an impasse over spending reductions in the next few weeks, automatic cuts are due to kick in by March 1, slashing roughly $US50 billion ($A48.89 billion) from the Pentagon's budget.
Obama paid tribute to Panetta's long career in politics, including his tenure as a member of Congress and in former president Bill Clinton's administration, when he served as budget chief and later as chief of staff.
Before taking over at the Pentagon, Panetta led the CIA from 2009-2011, presiding over an intelligence coup with the May 2011 raid that killed Al-Qaeda mastermind Osama bin Laden.