Iran's president has dismissed as propaganda the leaking of US cables detailing Arab calls for Washington to destroy Iran's nuclear facilities.
Mahmoud Ahmadinejad said the release by the Wikileaks website of thousands of extracts from US diplomatic messages was simply psychological warfare against Iran.
He said the release would not affect Iran's relations with other countries.
The US said the release was "reckless" and put the lives of diplomats at risk.
The Obama administration has been scrambling to make sure similar leaks do not happen again.
Government agencies have been ordered to tighten their procedures for handling classified information, ensuring that employees only have access to such documents as they need to do their jobs.
The Pentagon said it was making its computer systems more secure to prevent future leaks.
And Attorney General Eric Holder said there was an "active and ongoing criminal investigation" into the release of the documents and anyone found responsible would be prosecuted.
The founder of Wikileaks, Julian Assange, said the US authorities were afraid of being held to account.
European nations have roundly criticised the leaks, with France saying they represent a threat to democratic authority.
Pakistan's foreign ministry, meanwhile, condemned what it called "the irresponsible disclosure of sensitive official documents".
Among the revelations is a report that King Abdullah of Saudi Arabia had urged the US to destroy Iran's nuclear facilities.
Mr Ahmadinejad shrugged off the leaks at a televised news conference on Monday, saying no-one should waste time reviewing the information.
"We don't think this information was leaked," he said. "We think it was organised to be released on a regular basis and they are pursuing political goals."
On one level, the release of the Wikileaks documents may be highly damaging for Iran, says the BBC's Iran correspondent, James Reynolds.
For the first time - in black and white - we have proof that Arab countries have actively encouraged the United States to attack Iran, adds our correspondent, and from what we can tell, the documents paint a picture of Iran as isolated and under threat.
If this worries the Iranian government, it will not say so in public. Instead, adds our correspondent, Mr Ahmadinejad's response appears to conform to his overall world view - that every action of the United States is highly organised and aimed at promoting discord among Muslim nations.
The leaked cables written by US diplomats posted overseas contain blunt appraisals of their host governments, and unflattering pen portraits of world leaders.
US officials are said to have described Italian Prime Minister Silvio Berlusconi as feckless, vain and ineffective, sharing a close relationship with the "alpha dog" Russian Prime Minister Vladimir Putin.
President Nicolas Sarkozy of France is said to be thin-skinned and authoritarian, while German Chancellor Angela Merkel is described as risk-averse.
Afghan President Hamid Karzai is referred to as "extremely weak" and susceptible to conspiracy theories.
One US diplomat was said to be shocked at the "rude behaviour" of the British queen's second son, Prince Andrew, when abroad.
Meanwhile, Colonel Muammar Gaddafi of Libya always travels with a "voluptuous blonde" Ukrainian nurse, according to one of the cables.
Concerns aired include the security of Pakistani nuclear material that could fall into the wrong hands, allowing militants to make an atomic weapon. The widespread use of computer hacking by China's government is also reported.
Other issues reportedly covered in the cables are:
- Iranian attempts to adapt North Korean rockets for use as long-range missiles
- Corruption in Afghanistan with concerns heightened when a senior official was found to be carrying more than $52m (£33m) 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 to secure a meeting with President Barack Obama
- Germany being warned in 2007 not to enforce arrest warrants for CIA 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 leadership by Secretary of State Hillary Clinton
- Alleged links between the Russian government and organised crime, with intelligence agencies using underworld bosses to carry out operations
- Yemen's president talking to General David Petraeus (while he was responsible for US military operations in Central Asia and the Middle East as head of US Central Command) 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
Shedding light on wars?
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.
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."
Guardian editor Alan Rusbridger defended his newspaper's publication of leaked information, saying it was "not the job of the media to worry about the embarrassment of world leaders who have been caught saying different things in public or private, especially some of these Gulf states that don't have a free press".
No-one has been charged with passing the diplomatic files to Wikileaks, 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.
The cables release was the third mass Wikileaks release of classified documents since it published 77,000 secret US files on the Afghan conflict in July, and 400,000 documents about the Iraq war in October.
Wikileaks argues the release of the documents has shed light on the wars, including allegations of torture and reports that suggest 15,000 additional civilian deaths in Iraq.