• King Abdullah with Barack Obama. The leaks reveal the Saudi king repeatedly urging the US to attack Iran. Picture: Getty
In a leak that will have a political repercussions across the world stage, the confidential cables of US diplomats also provide strong criticism of the UK's military operations in Afghanistan, make claims of "inappropriate behaviour" by a member of the Royal Family, and ask for "specific intelligence" about MPs.
Numerous international leaders are also singled out for scathing ripostes by US officials, with Russia's Vladimir Putin described as an "alpha-dog", Iranian president Mahmoud Ahmadinejad compared to Hitler, and Afghan president Hamid Karzai deemed to be "driven by paranoia".
The disclosure of the hundreds of thousands of diplomatic cables by whistleblowing website WikiLeaks was a "reckless and dangerous action", said Robert Gibbs, a White House spokesman. The release of the classified material endangered lives and would "deeply impact" on US foreign policy interests and those of its allies, he said.
The material reportedly shows that the US effectively used its embassies as an espionage network, with diplomats charged with obtaining the frequent flyer numbers, credit card details and even DNA material from people they met.
Classified "human intelligence directives" issued in the name of secretary of state Hillary Clinton, or her predecessor, Condoleeza Rice, order officials to gather information on military installations, weapons markings, vehicles of political leaders, iris scans, fingerprints and DNA.
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Among those targeted in such a way were senior UN officials, the cables state, including secretary general Ban Ki-moon and the permanent security council representatives from Britain, China, Russia, and France. The directive to diplomats demands details of private communication networks including "passwords" and "personal encryption keys".
Elsewhere, the cables claim that King Abdullah of Saudi Arabia repeatedly urged the US to attack Iran, with Jordan, Bahrain and other Arab nations hoping for military action against Tehran.
The Saudi king was stated as having "frequently exhorted the US to attack Iran to put an end to its nuclear weapons programme," according to one cable.
"He told you (Americans] to cut off the head of the snake," the Saudi ambassador to Washington, Adel al-Jubeir, said, according to a report on King Abdullah's meeting with the US general David Petraeus in April 2008.
The New York Times, given early access to the cables, reported that Iran bought 19 advanced missiles from North Korea, giving it the capacity to strike at capitals in western Europe. The newspaper also states that US diplomats ordered the Slovenian government to take a prisoner from Guantanamo Bay if it wanted to meet with President Barack Obama, while the island nation of Kiribati was offered incentives worth millions of dollars to take in a group of detainees.
US officials, the material reveals, suggested that accepting more prisoners would be "a low-cost way for Belgium to attain prominence in Europe".
Der Spiegel, the German news magazine, revealed that US diplomats were sceptical about Turkey's dependability as a partner. The leadership in Ankara is depicted as divided and permeated by Islamists.
Other damaging revelations suggest that Saudi donors remain chief financiers of militant groups such as al-Qaeda and that Chinese government operatives have waged a co-ordinated campaign of computer sabotage targeting the US and its allies.
Separate documents are said to disclose technical details of secret US-Russian nuclear missile negotiations in Geneva and clandestine US efforts to combat al-Qaeda in Yemen.
There is a description of Libyan leader, Colonel Muammar al-Gaddafi, who is said to be accompanied everywhere by a "voluptuous blonde" Ukrainian nurse.
Documents also reveal that Geoffrey Adams, Britain's ambassador to Iran, gave the US advice on how to negotiate with Tehran. He told the Americans in his briefing: "Iranians are obsessed with the West and this obsession at times blinds them to their interests."
The extraordinary wave of disclosures, which number about 250,000 cables, are just the first in a series of leaks to be made by WikiLeaks, with about 2.5 million cables due to be published in all.
Later disclosures are widely expected to reveal Washington's "serious political criticisms" of Prime Minister David Cameron, and reveal secret discussions surrounding the release of Abdelbaset Ali Mohmed al-Megrahi, the Lockerbie bomber.