Bryan Whitman, a senior spokesman for the defence department, responded to the broadcast by Australian television network SBS of previously unpublished images of prisoner abuse.
"The department believes that a further release of images could only further inflame and possibly incite unnecessary violence in the world and would endanger our military men and women that are serving around the world," he said.
Whitman said he did not know whether US officials had reviewed the photos and video clips or whether they were among a group of images the department had been withholding from public release since 2004.
Images depicting scenes of abuse released at the end of 2004 embroiled the US administration in scandal, and 27 military intelligence staff were implicated. A report suggested that senior prison officials knew of the abuse but failed to intervene to stop it.
Mike Carey, an SBS representative, told the BBC that the new images represented "a leap in seriousness" from those previously seen.
This photo shows a prisoner
covered in faeces (SBS)
A defence official, speaking on condition of anonymity, said army representatives had reviewed the photographs posted on the Sydney Morning Herald's website and matched them to images that were among those turned over to military authorities in Iraq in 2004 by a US soldier.
The official said no new information about abuse could be garnered from the photos.
Based on Whitman's comments, it appeared that the Pentagon did not intend to open a new investigation as a result of the latest publication.
Donald Rumsfeld, the defence secretary, cancelled a routine Pentagon news conference on Wednesday afternoon, but his staff said this was merely due to scheduling reasons.
Rumsfeld himself faced fierce criticism after the initial publication of photos in 2004 and said he twice offered his resignation to George Bush.
Some photos are similar to those
already published (SBS TV)
Whitman said the abuses at Abu Ghraib have been fully investigated.
"When there have been abuses, this department has acted on them promptly, investigated them thoroughly and where appropriate prosecuted individuals," he said.
More than 25 people have been held accountable for criminal acts and "other failures" at Abu Ghraib, Whitman said.