The top US military officer said the Pentagon is trying to protect Afghans who may be at risk from Taliban retaliation following the publication of tens of thousands of secret war documents.
Admiral Mike Mullen, chairman of the Joint Chiefs of Staff, says the US is duty-bound to try to shield informants who were named in the documents.
Taliban spokesmen have said that their organisation will use the material to try to hunt down people who've been co-operating with what the Taliban considers a foreign invader.
The website WikiLeaks posted nearly 77,000 secret documents a week ago, leading to wide condemnation from US officials.
Admiral Mullen was interviewed on CBS television's Face the Nation and NBC's Meet The Press.