The United Nation's nuclear watchdog has failed to convince Iran of the need to inspect a military base suspected of housing nuclear weapons' experiments, Iranian media cited the head of country's atomic agency as saying on Saturday.

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Comments reportedly made by the head of Atomic Energy Agency of Iran (AEOI) Fereidoun Abbasi came despite last week's announcement of a burgeoning deal between Iran and the International Atomic Energy Agency (IAEA), according to which the international community would have more access to the Parchin base.

Speaking on Tuesday, IAEA chief Yukiya Amano, who had been looking for a deal giving his inspectors a freer hand to investigate suspected atomic bomb research in Iran, described the outcome of his meetings in Iran as an "important development."

He said he had raised the issue of access to the Parchin military site - an IAEA priority in its inquiry - and that this would be addressed as part of the agreement's implementation.

However, Iran's state-run TV and semi-official Fars news agency both cited
Abbasi as saying Saturday that Iran had not been convinced of the need to inspect the Parchin site, adding that "no documents or reason has been presented to us" to persuade Tehran otherwise.

According to the Iranian nuclear chief, the UN's nuclear watchdog "is interested in visiting Parchin due to pressure from countries that want the agency to investigate the issue," reiterating Iran's refusal to stop enrichment: "We do not ask for permission from anyone to meet our country’s demands.”

“It would be better for them to negotiate with our country with regards to obtaining fuel and not ask us to stop producing fuel,” Abbasi added.

"There is no reason for us to give up enriching uranium to 20 percent because we produce this fuel only to meet our needs, no more and no less," He said.

Abbasi's remarks were made the U.S. Institute for Science and International Security (ISIS) claimed that Iran has significantly stepped up its output of low-enriched uranium and total production in the last five years would be enough for at least five nuclear weapons if refined much further.

ISIS, a think-tank which tracks Iran's nuclear program closely, based the analysis on data in the latest report by the IAEA which was issued on Friday.

The IAEA report suggested it was possible that particles of uranium enriched to higher-than-declared levels could be the result of a technical phenomenon. Experts say that while it is embarrassing for Iran, there is no real cause for concern.

The UN agency also said satellite images showed "extensive activities" at the Parchin military complex which inspectors want to check over suspicions that research relevant to nuclear weapons was done there.

Earlier this month, an image said to come from inside the Parchin base and showing an explosives containment chamber of the type needed for nuclear arms-related tests that UN inspectors suspect Tehran has conducted at the site.

The image was provided to The Associated Press by an official of a country tracking Iran's nuclear program who said the drawing proves the structure exists, despite Tehran's refusal to acknowledge it.

The official said he could not discuss the drawing's origins beyond that it =was based on information from a person who had seen the chamber at the Parchin military site, adding that going into detail would endanger the life of that informant. His country, a member of the International Atomic Energy Agency, is severely critical of Iran's assertions that its nuclear activities are peaceful and asserts they are a springboard for making atomic arms.