US President George W Bush has assured Defence Secretary Donald Rumsfeld of his "full support" in the wake of criticism by retired generals.
Rumsfeld has been accused of ignoring advice from commanders
In a statement, the president rejected calls for Mr Rumsfeld to step down.
Mr Bush praised Mr Rumsfeld for his "energetic and steady leadership" during his years at the Pentagon.
Six retired generals have spoken out against Mr Rumsfeld's handling of the war in Iraq and apparent disdain for experienced military commanders.
The defence secretary has also personally dismissed suggestions that he should resign.
"Out of thousands and thousands of admirals and generals, if every time two or three people disagreed we changed the secretary of defence of the United States it would be like a merry-go-round," he told Arabic TV channel al-Arabiya.
But he did admit to regrets over the abuse of prisoners by US troops at Baghdad's Abu Ghraib jail.
He offered his resignation during the 2004 furore over Abu Ghraib, but Mr Bush refused to accept it.
In his statement, Mr Bush dismissed claims that the defence secretary has not worked well with senior commanders.
"I have seen first-hand how Don relies upon our military commanders in the field and at the Pentagon to make decisions about how best to complete these missions," Mr Bush said.
CRITICAL RETIRED GENERALS
Maj Gen Charles H Swannack Jr, Army
Maj Gen John Riggs, Army
Maj Gen John Batiste, Army
Gen Anthony Zinni, Marines
Lt Gen Gregory Newbold, Marines
Maj Gen Paul Eaton, Army
"Secretary Rumsfeld's energetic and steady leadership is exactly what is needed at this critical period," he added.
"He has my full support and deepest appreciation."
The president stressed that under Mr Rumsfeld's guidance the US military has undergone a period of rapid transformation and faced a series of major overseas conflicts.
"That kind of change is hard, but our nation must have a military that is fully prepared to confront the dangerous threats of the 21st Century."
Mr Bush's support comes as US-based Human Rights Watch said Mr Rumsfeld could be "criminally liable" for what it described as the torture of a detainee at Guantanamo Bay.
The organisation urged the US to appoint a special prosecutor to investigate the case after documents suggested the defence secretary had been "personally involved" in the interrogation of the Saudi al-Qaeda suspect in 2002 and 2003.
It referred to parts of an army inspector general's report from December 2005, obtained by online magazine Salon.com, which said Mr Rumsfeld had talked weekly to the Guantanamo commander about the interrogation.
The BBC's Jane Little in Washington says it is highly unusual for Mr Bush to issue a statement from his Camp David retreat, where he is on holiday - but pressure is mounting on Mr Rumsfeld and the administration.
The Democrats have seized on it, comparing the president's support with the praise he gave to Michael Brown, former head of the Federal Emergency Management Agency (Fema), over his handling of the Hurricane Katrina aftermath.
Despite Mr Bush's approval, Mr Brown was forced out of office after harsh criticism of the government's response to the disaster.
Mr Bush's unequivocal backing for Mr Rumsfeld came amid growing discontent among recently-retired senior officers.
Among those voicing their unease were Maj Gen John Riggs and Maj Gen Charles H Swannack Jr, both of the Army.
In a radio interview Gen Riggs, a former division commander, said Mr Rumsfeld fostered an atmosphere of "arrogance" among the Pentagon's top civilian leadership.
Mr Rumsfeld twice offered to resign over the Abu Ghraib scandal
"They only need the military advice when it satisfies their agenda. I think that's a mistake, and that's why I think he should resign," he told National Public Radio (NPR).
Retired Marine Gen Anthony Zinni told CNN Mr Rumsfeld should be held responsible for a series of mistakes, beginning with "throwing away 10 years worth of planning, plans that had taken into account what we would face in an occupation of Iraq".
But others have come out in support of the embattled defence secretary.
Retired Marine Lt Gen Mike DeLong, who was deputy commander of Central Command as the US military prepared to invade Iraq in March 2003, said Mr Rumsfeld was good at his job.