The Pentagon says WikiLeaks may have more classified U.S. material than previously thought.
The website of the international anti-secrecy group has already posted half a million secret Iraq and Afghanistan war files since July.
The group is also believed to have another 15,000 Afghan war field reports, 260,000 diplomatic cables and U.S. video of casualties in Afghanistan.
Defense Department spokesman Col. Dave Lapan told reporters Tuesday the Pentagon suspects the group may have even more classified U.S. data than previously reported, but declined to characterize it.
The U.S. has said that the release of secret Afghan and Iraq war documents threatens national security.