The Pentagon has demanded that WikiLeaks hand over a new stash of 15,000 new documents relating to the war in Afghanistan, and called on the whistle-blowing site to remove all classified information already posted.
In a press briefing, Defense Department spokesman Geoff Morrell demanded that the site cancel the release of the 15,000 as-yet-unpublished documents
"We are asking them to do the right thing," he told reporters.
Morrell denied that the Pentagon had been in contact with WikiLeaks over a request by the site for help in reviewing the new documents so that any content which might endanger lives might be safely redacted.
"We're not looking to have a conversation about harm minimisation," Mr Morrell said.
"We're looking to have a conversation about how to get these perilous documents off the website as soon as possible, return them to their rightful owners and expunge them from their records."
The denial is in direct contradiction of a statement made on Wednesday by WikiLeaks spokesman Daniel Schmitt.
Morrell went on to say that statements on WikiLeaks' website constitutes a "brazen solicitation to US government officials, including our military, to break the law."
WikiLeaks responded by calling Morrell "obnoxious". On its official Twitter feed, the site described Morrell's demand as coming close to a "formal threat".
The site remained in defiant mood this morning, with a post on its Twitter feed reading: "We are examining the Pentagon's 'request' and will issue a statement in due course."
Pressure has mounted on WikiLeaks since it released a first batch of documents concerning the Afghanistan war on 25 July. US government sabre-rattling led to an offer of secure hosting from Sweden's Pirate Party, in the event of the site's existing host being forced to pull its pages down.
US Defense Secretary Robert Gates and the US military's highest officer, Admiral Mike Mullen, have claimed that the leak has put innocent civilian lives in jeopardy.
Further speculation as to the site's future has been sparked by the appearance of a 1.4GB file labelled 'insurance' on its servers.