Washington (CNN) -- The Pentagon fears that the 15,000 leaked documents about the war in Afghanistan that website WikiLeaks says it will soon post are "potentially even more damaging" than the more than 70,000 already published, said Pentagon spokesman Col. Dave Lapan.
The Pentagon does not know exactly what is in the new documents, but that officials "have looked at what we believe is the source of those documents, as well as the Task Force assessment of what's already out there," said Lapan.
The Pentagon is still hopeful Wikileaks will not publish the documents and "are concerned the new release will cause even greater risk to the troops," he said.
WikiLeaks has said it intends to publish the additional 15,000 documents soon, but is reviewing them to edit out names. At a press conference in London, England, on Thursday, WikiLeaks' founder Julian Assange said the company was about halfway through reviewing the documents.
The site has come under criticism from humanitarian groups who warned that the release of documents naming civilians that work with international forces could endanger lives. Assange has been asked by those groups to further censure those documents already published in addition to being more careful in releasing documents going forward.
Meanwhile, the Pentagon is looking at ways to better protect information, said Lapan. There "have been no broad changes yet" in how the military allows access to classified material, said Lapan. But officials are looking at ways to better balance the need for information with the risk of security breach. "There's nothing concrete yet, but we're certainly looking at that."