The Pentagon tonight demanded that whistle-blower web site WikiLeaks immediately hand over about 15,000 secret Afghan war records it had not yet published and erase material it had already put online.
"We are asking them to do the right thing," said Pentagon spokesman Geoff Morrell in asking WikiLeaks to hand over the US documents and delete material it had put on the Internet.
"We hope they will honor our demands," he told reporters, adding that the only rightful owner of all the classified material in WikiLeaks possession was the US government.
The whistle-blower site caused uproar when it published more than 70,000 documents last month, coming at a time when US public and congressional support for the nine-year war in Afghanistan is flagging.
The defence department said the leak - one of the largest in US military history - put US troops and Afghan informers at risk and WikiLeaks might already have blood on its hands.
WikiLeaks founder Julian Assange has said his group held back about 15,000 papers to protect innocent people from harm and Morrell said the appeal for documents to be returned was to prevent publication of material that could cause further damage.
Asked whether the defence department would take legal action against WikiLeaks if it refused to comply with the demand, Mr Morrell declined to give specifics but said it was up to the FBI and the Justice Department to decide how to proceed.
"If doing the right thing is not good enough for them, then we will figure out what other alternatives we have to compel them to do the right thing," he added.
Mr Morrell said public disclosure of the secret documents, which included names of Afghan informers, had already caused damage and a bid to get the information permanently deleted from the web site and all the documents returned was aimed at minimizing further harm.
WikiLeaks also has a large, encrypted file on its web site titled "insurance" which has not been released to the public, and the Pentagon is jittery over the possible publication of more unknown material.
Mr Morrell said a task force of about 80 government intelligence experts were painstakingly combing through the 70,000 or so documents which had already been released and were notifying foreign governments and others when material was seen as posing a risk.
The intelligence analysts had done about 400 initial "word searches" of the documents and were working around the clock to analyze the material in greater depth, Morrell added.
Mr Morrell said the department had an idea over what might be in the 15,000 unreleased documents and was doing "prophylactic work" in case WikiLeaks ultimately posted this material. He declined to give details.
The US investigation is focusing on Bradley Manning, who worked as an Army intelligence analyst in Iraq. Mr Manning is already under arrest and charged with leaking a classified video showing a 2007 helicopter attack that killed a dozen people in Iraq.
Reuters