The White House condemned WikiLeaks' ‘reckless and dangerous action’ in releasing classified US diplomatic cables, saying it could endanger lives and risk hurting relations with friendly countries.

US State Department documents released by the whistle-blowing website provided candid views of foreign leaders and sensitive information on terrorism and nuclear proliferation, the New York Times reported.

The documents show Saudi donors remain chief financiers of militant groups like al Qaeda and that Chinese government operatives have waged a coordinated campaign of computer sabotage targeting the United States and its allies, according to a review of the WikiLeaks documents published in the Times.

‘These cables could compromise private discussions with foreign governments and opposition leaders, and when the substance of private conversations is printed on the front pages of newspapers across the world, it can deeply impact not only U.S. foreign policy interests, but those of our allies and friends around the world,’ White House spokesman Robert Gibbs said in a statement.

By their nature, the cables often contained incomplete information and were not an expression of policy, he 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,’ Mr Gibbs said.

He said the cables may include the names of pro-democracy activists living "under oppressive regimes."

‘By releasing stolen and classified documents, WikiLeaks has put at risk not only the cause of human rights but also the lives and work of these individuals,’ he said.

Leaked cables include claims of "inappropriate behaviour" by a member of the British royal family and request for ‘specific intelligence’ about British MPs.

The Guardian newspaper, which is one of a number of newspapers to have advance sight of the 250,000 classified documents released by WikiLeaks said they include criticisms of David Cameron and of British military operations in Afghanistan.

On the international front, the cables were said to disclose that Arab leaders were privately urging the United States to carry out an air strike on Iran, according to an article on the newspaper's website.

It also said that US diplomats had been instructed to spy on the leadership of the United Nations.