The Pentagon says it could take weeks to assess the damage from the leak of more than 90,000 documents about the war in Afghanistan.
Documents, published online at the website Wikileaks, detail the war in Afghanistan, including previously unreported civilian deaths.
The BBC reports they reveal concerns within NATO that Pakistani intelligence helped the Taliban - something Islamabad denies.
The White House condemned the leak as a possible threat to national security.
Wikileaks describes the documents as battlefield and intelligence reports compiled by a variety of military units during the period 2004-09.
The White House said the leak did not divulge anything new about the nature of the war in Afghanistan, but the details revealed, could be damaging.