They include reports of some Arab leaders - including Saudi Arabia's King Abdullah - urging the US to attack Iran and end its nuclear weapons programme.

Other concerns include the security of Pakistani nuclear material that could be used to make an atomic weapon.

The widespread use of computer hacking by China's government is also reported.

The US government condemned the release of the documents, which number in the hundreds of thousands, saying they put the lives of diplomats and others at risk.

The founder of Wikileaks, Julian Assange, countered by saying the US authorities were afraid of being held to account.

So far, Wikileaks has only posted some 200 of the 251,287 messages it says it has obtained. However, the entire bundle of cables has been made available to five publications, including the New York Times and the UK’s Guardian newspaper.