WikiLeaks could destroy US relations worldwide

The US ambassador to Iraq has labelled WikiLeaks "absolutely awful" for US relations, as government panic mounts over a WikiLeaks threat to expose "secret diplomatic backroom dealings" that could destroy the superpower's standing worldwide.

"We are worried about additional documents coming out," ambassador Jeffrey James told a press briefing this morning, as reports poured in of a flurry of diplomatic activity worldwide.

The whistle-blowing site revealed in a series of posts on micro-blogging site Twitter that US officials have conducted a series of emergency meetings with high-ranking foreign government officials.

In the UK, Sky News reported that the US Ambassador Louis Susman has visited Downing Street in advance of the leak for what one source called "contingency planning".

The Sydney Morning Herald claimed US Secretary of State Hilary Clinton had briefed Australian Foreign Minister Kevin Rudd on the leak.

Elsewhere in the world, reports have come in of high-level meetings between US officials and governments in Canada, Denmark and Norway.

Israeli newspaper Haaretz confirmed that the country's government had been contacted by the US embassy in Tel Aviv.

The cause of the frantic politicking is WikiLeaks' expected disclosure of a huge volume of secret cables between US diplomatic outposts and State Department headquarters in Washington.

The whistle-blowing site alerted followers to the impending leak earlier this week, with a post on Twitter revealing that it was to release of a tranche of documents "seven times bigger" than the recent Iraq War Dossier, adding cryptically that "The coming months will see a new world, where global history is redefined.".

That batch of classified files concerning the war in Iraq included some 391,000 documents. If, as suggested, the coming leak totals more than 2.5 million communications, its impact on US diplomatic relations could be catastrophic.

Acknowledging the effect such a leak would have, State Department spokesman PJ Crowley admitted: "These revelations are harmful to the United States and our interests. They are going to create tension in relationships between our diplomats and our friends around the world."