The next leak of secret Afghan war documents being planned by WikiLeaks will be even more damaging to US security and the war effort than the initial release of 76,000 war files, the Pentagon has warned.
Pentagon press secretary Geoff Morrell said the military believes it has identified the additional 15,000 classified documents that WikiLeaks has vowed to release.
He would not identify the documents but stressed their exposure would be even more damaging than the thousands already published.
Last month, WikiLeaks posted online 77,000 classified US military reports covering the war in Afghanistan from 2004 to 2010, an extraordinary disclosure which some say could expose human rights abuses across the Nato-led campaign.
The Pentagon has accused WikiLeaks of endangering the lives of soldiers and informants in the field, and demanded that WikiLeaks refrain from publishing any more secret data.
But speaking via videolink to London's Frontline Club, WikiLeaks spokesman Julian Assange said he had no intention of holding back the documents.
He gave no specific time frame for their release, but said his organisation was about halfway through those 15,000 or so secret files previously held back from publication.
"We're about 7,000 reports in," he said, adding that he would definitely publish them. There was no indication as to whether he would give the documents to The New York Times, The Guardian, and Der Spiegel - as he did before - or simply publish them on his website.
Mr Assange is under pressure from US authorities who have thrown the resources of the military and the FBI into investigating the source of his scoop. The Pentagon has a task force of about 100 people reading the leaked documents to assess the damage done and working, for instance, to alert Afghans who might be identified by name and now could be in danger.
Reporters Without Borders criticised the planned leak of more documents, saying WikiLeaks was showing "incredible irresponsibility". The international media watchdog said that while the whistleblower group had often played a useful role, revealing the identity of Afghan informants "is highly dangerous".