Media playback is unsupported on your device Media caption Hillary Clinton: 'It is an attack on the international community'

Whistle-blowing website Wikileaks has begun releasing extracts from secret cables sent by US embassies, giving an insight into current global concerns.

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.

The leaked US embassy cables also reportedly include accounts of:

Analysis The fact that the Saudis, Jordanians and others are deeply suspicious about Iran's intentions is well known. What has not been known until now is how strongly they have been pressing for American military action. The leaks do not tell the Iranians anything they did not suspect, or perhaps have already picked up themselves. But they will sharpen the debate over Iran's nuclear plans, and about the chances of military action by the Americans - or the Israelis. The leaks are deeply embarrassing for the Americans, and will infuriate Arab leaders whose remarks have been quoted. Commentators: Diplomatic disaster or just embarrassing?

Iran attempting to adapt North Korean rockets for use as long-range missiles

Corruption within the Afghan government, with concerns heightened when a senior official was found to be carrying more than $50m in cash on a foreign trip

Bargaining to empty the Guantanamo Bay prison camp - including Slovenian diplomats being told to take in a freed prisoner if they wanted to secure a meeting with President Barack Obama

Germany being warned in 2007 not to enforce arrest warrants for US Central Intelligence Agency officers involved in an operation in which an innocent German citizen with the same name as a suspected militant was abducted and held in Afghanistan

US officials being instructed to spy on the UN's leadership by Secretary of State Hillary Clinton

The very close relationship between Russian PM Vladimir Putin and his Italian counterpart Silvio Berlusconi

Alleged links between the Russian government and organised crime

Yemen's president talking to then US Mid-East commander General David Petraeus about attacks on Yemeni al-Qaeda bases and saying: "We'll continue saying the bombs are ours, not yours"

Faltering US attempts to prevent Syria from supplying arms to Hezbollah in Lebanon

The leaked embassy cables are both contemporary and historical, and include a 1989 note from a US diplomat in Panama City musing about the options open to Panamanian leader Manuel Noriega and referring to him as "a master of survival" - the author apparently had no idea that US forces would invade a week later and arrest Noriega.

Wikileaks Whistle-blowing website with a reputation for publishing sensitive material

Run by Julian Assange, a secretive Australian with a background in computer network hacking

Released 90,000 secret US records of US military incidents about the war in Afghanistan and 400,000 similar documents on Iraq

Also posted video showing US helicopter killing 12 people - including two journalists - in Baghdad in 2007

Other controversial postings include screenshots of the e-mail inbox and address book of US vice-presidential candidate Sarah Palin What is Wikileaks? Profile: Julian Assange

In a statement, the White House said: "Such disclosures put at risk our diplomats, intelligence professionals, and people around the world who come to the United States for assistance in promoting democracy and open government.

"President Obama supports responsible, accountable, and open government at home and around the world, but this reckless and dangerous action runs counter to that goal."

Earlier, Wikileaks said it had come under attack from a computer-hacking operation.

"We are currently under a mass distributed denial of service attack," it reported on its Twitter feed.

No-one has been charged with passing the diplomatic files to the website but suspicion has fallen on US Army private Bradley Manning, an intelligence analyst arrested in Iraq in June and charged over an earlier leak of classified US documents to Mr Assange's organisation.

Wikileaks argues that the site's previous releases shed light on the wars in Afghanistan and Iraq.