President Muhammad Khatami said on Wednesday the report on Iran's nuclear programme proved his country was telling the truth all along.
And he said criticism of Iran in the report was just "trumped-up statements".
Khatami was speaking two days after the release of an International Atomic Energy Agency (IAEA) report which said it found no evidence of an Iranian nuclear weapons programme.
But the IAEA also suggested it could not rule out such ambitions until it sifted through new information only recently made available by the Iranians after nearly two decades of cover-ups.
Referring to the head of the IAEA, Muhammad al-Baradei, Khatami said: "The most positive point in Mr al-Baradei's report is that it has been announced there is nothing to suggest that the Islamic Republic of Iran is pursuing nuclear weapons."
"This proves our claim and removes the possibility for some powers to misuse the situation against us."
"Naturally, over 20 years of nuclear activity, some failures did occur. We do not deny this. But it does not mean we violated or transgressed the regulations of the Nuclear Nonproliferation Treaty"
The document listed numerous cases of covert nuclear activities, including uranium enrichment and the production of a small amount of plutonium that effectively put Iran in violation of part of the Nuclear Nonproliferation Treaty.
But it also praised Iran for its recent "active cooperation and openness".
The United States had been lobbying for the IAEA board, which meets on 20 November in Vienna, to formally declare Iran in violation of the Nonproliferation Treaty.
If approved, this move could lead to sanctions on Iran imposed by the UN Security Council.
Khatami acknowledged Iran had shortcomings, but he denied these constituted a violation of the treaty.
Bolton is the US's top official on
"Naturally, over 20 years of nuclear activity, some failures did occur. We do not deny this. But it does not mean we violated or transgressed the regulations of the Nuclear Nonproliferation Treaty, to which we are committed," he said.
However, US Undersecretary of State John Bolton said on Wednesday that the IAEA's findings were "impossible to believe".
Bolton said the report actually reaffirms the US belief that "the massive and covert Iranian effort to acquire sensitive nuclear capabilities make sense only as part of a nuclear weapons programme".
"The report's assertion is simply impossible to believe"
US Undersecretary of State
Although the IAEA extensively documented Iran's denials and deceptions over an 18-year period and listed numerous Iranian violations of international nuclear commitments, "the report nonetheless concluded that no evidence had been found of an Iranian nuclear weapons programme.
"The report's assertion is simply impossible to believe," said Bolton, the Bush administration's chief official in charge of arms control and nonproliferation policy.
Bolton said this week's report, coupled with two previous reports, "have established that Iran is in violation - in multiple instances - of its safeguards obligations under the Nuclear Nonproliferation Treaty".
If Iran takes all the steps demanded of it - including providing full transparency on its nuclear activities and allowing snap inspections - this would be a "major advance towards its integration into civilised society," he said.
But if Tehran continues to conceal its nuclear programme and "lie to the IAEA, the international community must be prepared to declare Iran in noncompliance with its IAEA safeguards obligations."