The Pentagon has assembled a 120-member team prepared ahead of the expected publication of as many as 500,000 Iraq war documents by the WikiLeaks website.
Pentagon spokesman Col. Dave Lapan said the timing of the leak remained unclear but the Defense Department was ready for a document dump as early as today or tomorrow, a possibility raised in previous WikiLeaks statements.
If confirmed, the leak would be much larger than the record-breaking release of more than 70,000 Afghan war documents in July, which stoked debate about the 9-year-old conflict but did not contain major revelations.
It was the largest security breach of its kind in US military history.
"It's the same team we put together after the publication of the (Afghan war documents)," Col. Lapan said, adding it was unclear how many of the 120 personnel would be needed to contribute to the Iraq leak analysis.
Although the Iraq conflict has faded from public debate in the United States in recent years, the document dump threatens to revive memories of some of the most trying times in the war, including the Abu Ghraib prisoner abuse scandal.
It could also renew debate about foreign and domestic actors influencing Iraq, which has been wrestling with a political vacuum since an inconclusive election in March.
One source familiar with the Iraq documents said they are likely to contain revelations about civilian casualties, but expected them to cause less of a stir than the Afghan leak.
Col Lapan said the Pentagon team believed it knew which documents WikiLeaks may be releasing since it had already reviewed the Iraq war file. That could speed up its assessment about potential fallout.
WikiLeaks says it is a non-profit organisation funded by human rights campaigners, journalists and the general public. But the Pentagon has demanded it return classified information and critics have questioned its perceived anti-war agenda.
So far the investigation into the Afghan war leak has focused on Bradley Manning, who worked as an Army intelligence analyst in Iraq.
Mr Manning is already under arrest and charged with leaking a classified video showing a 2007 helicopter attack that killed a dozen people in Iraq, including two Reuters journalists.
The Pentagon, citing the criminal investigation, has refused to discuss the Manning case.
Elsewhere, Sweden today denied a work and residency permit for WikiLeaks founder Julian Assange.
Mr Assange has been establishing a base in Sweden in order to benefit from the Nordic country's strict journalist protection laws. He is also being investigated over rape allegations in Sweden, which he has denied, calling them baseless.
"The board today rejected Assange's application for a work and residency permit," said a spokesman at the Swedish Migration Board. He gave no reason for the rejection of the permit, citing confidentiality rules.
Mr Assange, an Australian citizen, can appeal the decision within three weeks.
Reuters