LONDON – WikiLeaks spokesman Julian Assange said Thursday his organization is preparing to release the rest of the secret Afghan war documents it has on file. The Pentagon warned that would be more damaging to security and risk more lives than the organization’s initial release of some 76,000 war documents.

That extraordinary disclosure, which laid bare classified military documents covering the war in Afghanistan from 2004 to 2010, has angered U.S. officials, energized critics of the NATO-led campaign and drawn the attention of the Taliban, which has promised to use the material to track down people it considers traitors.

The Pentagon says it believes it has identified the additional 15,000 leaked classified documents.

Pentagon Press Secretary Geoff Morrell described the prospective publication as the “height of irresponsibility.”

“It would compound a mistake that has already put far too many lives at risk,” he said.

Speaking via videolink to London’s Frontline Club, Assange brushed aside the Pentagon’s demands that he stop publishing their intelligence. He gave no specific time frame for the release of the 15,000 remaining files, but said his organization had gone through about half of them.

“We’re about 7,000 reports in,” he said, describing the process of combing through the files to ensure that no Afghans would be hurt by their disclosure as “very expensive and very painstaking.”

Still, he told the audience that he would “absolutely” publish them. He gave no indication whether he would give the documents to media outlets The New York Times, The Guardian and Der Spiegel — as he has before — or simply dump them on the WikiLeaks website.

The leaks exposed unreported incidents of Afghan civilian killings by NATO forces and covert operations against Taliban figures. Assange has said that hundreds of those reports should be investigated by the media for evidence of war crimes.

WikiLeaks’ supporters say the blow-by-blow account of the conflict reveals the horror of the campaign’s daily grind. Detractors say the site has recklessly endangered the war effort and Afghan informants working to stop the Taliban.

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.

Taliban spokesmen have said they would use the material to try to hunt down people who’ve been cooperating with what the Taliban considers a foreign invader.

That has aroused the concern of human rights groups working in Afghanistan — as well as Paris-based media watchdog Reporters Without Borders, which on Thursday accused WikiLeaks of recklessness.

“WikiLeaks has in the past played a useful role by making information available that exposed serious violations of human rights and civil liberties,” said Jean-Francois Julliard, the group’s secretary-general, in an open letter to Assange.

“But revealing the identity of hundreds of people who collaborated with the coalition in Afghanistan is highly dangerous.”

Defense Department spokesman Col. David Lapan dismissed WikiLeaks’ claims that it was removing information that could harm civilians.

“They don’t have the expertise to determine what might be too sensitive to publish,” he said.