BERLIN: NATO chief Anders Fogh Rasmussen on Friday warned that the lives of soldiers and civilians could be endangered if the whistleblowing Wikileaks website releases more secret military documents.
The WikiLeaks website has promised a "major announcement" in Europe on Saturday, in a message on its Twitter feed, amid speculation it will release a tranche of secret documents about the Iraq war.
"Major WikiLeaks announcement in Europe at 10am tomorrow," said the message, appearing to confirm that the site is preparing to leak what the US military and NATO fear will be tens of thousands of classified military papers.
"Such leaks are very unfortunate and may have very negative security implications for people concerned," Rasmussen said during a joint press conference with German Chancellor Angela Merkel in Berlin.
"Leaks may put soldiers as well as civilians at risk," he added.
WikiLeaks announced Monday it would be releasing more documents "very soon", but did not specify exactly what was coming. A message posted on its Twitter page also said, "Major WikiLeaks press conference in Europe coming up."
"We don't comment on what we are working on and don't give any exact dates," Kristinn Hrafnsson, a close collaborator of founder Julian Assange, told AFP.
The US Pentagon said last week a 120-strong taskforce was scouring an Iraq war database to prepare for potential fallout from an expected release by WikiLeaks of some 400,000 secret military reports.
It appealed to the media to avoid facilitating the leak of documents regarding Iraq.
"News organisations should be cautioned not to facilitate the leaking of classified documents with this disreputable organisation known as WikiLeaks," Pentagon spokesman Colonel Dave Lapan told reporters.
Helping the website publish the classified records could "provide a veneer of legitimacy to WikiLeaks," he said.
But Lapan did not threaten legal action and said so far no news outlet had indicated it intended to cooperate with WikiLeaks.
"We have not been approached specifically by news organizations about the release," Lapan said.
US newspapers have argued that media outlets are under no legal obligation to obey secrecy rules designed to apply to government employees, and that in the past the publication of classified documents has served the public interest.
But in a tweet on the micro-blogging networking site Twitter, Wikileaks said: "We did not say we were publishing something on Iraq."
The whistleblower website published 77,000 classified US military documents on the war in Afghanistan in July and is expected to publish another 15,000.
The documents, revealing details of civilian victims and supposed links between Pakistan and the Taliban insurgents infuriated the Pentagon.
Human rights groups were also worried that the names of Afghans aiding the US forces had not been erased, laying them open to reprisals.
WikiLeaks first released those files to three publications, the New York Times, the Guardian and Der Spiegel, but it was unclear if the website would take a similar approach with the Iraq documents.
WikiLeaks has not identified the source of the documents it obtained but suspicion has fallen on Bradley Manning, a US Army intelligence analyst who is currently in military custody.
Manning was arrested in May following the release by WikiLeaks of video footage of a US Apache helicopter strike in Iraq in which civilians died and has been charged with delivering defence information to an unauthorized source.