The U.N. nuclear watchdog chief said on Thursday Iran had vowed to answer outstanding concerns about its nuclear program and was willing to accept tougher inspections of sites, where Washington says bombs could be made.

But Iranian officials told Mohamed ElBaradei they still had misgivings about signing the Additional Protocol of the nuclear Non-Proliferation Treaty (NPT) on snap inspections and wanted to carry on negotiating the issue.

ElBaradei's visit came just two weeks before an October 31 U.N. deadline for Iran to disprove U.S.-led claims it has a secret atomic weapons program. Failure to do so could see Iran's case referred to the U.N. Security Council in November.

A senior Iranian official said the foreign ministers of Britain, France and Germany would fly to Tehran next week to try to resolve the nuclear standoff before the deadline.

"Yes, they are coming to Iran next week," the official told reporters when asked about the visit.

ElBaradei arrived in Tehran Wednesday overnight warning that Iran had still not provided the International Atomic Energy Agency (IAEA) with the full disclosure it was seeking.

Speaking to reporters after a meeting in Tehran with Iran's Supreme National Security Council chief Hassan Rohani, ElBaradei said: "I was assured by Dr Rohani that the Islamic Republic of Iran will clarify all the outstanding issues for us to be able to verify all aspects of Iran's nuclear activities."

Asked on his way to the airport to leave for Vienna whether Iran had promised to stop enriching uranium, he said: "No. The board of governors (of the IAEA) have asked them to suspend it as a confidence building measure, but I think they are still thinking about it, there is no decision."

IAEA HOPES FOR COMPLETE DECLARATION

Asked if he though Iran was going to make full disclosure, ElBaradei said: "I hope we will get to a complete declaration of their nuclear activities, so I hope that next week we will see steps that could be positive."

IAEA spokeswoman Melissa Fleming said the IAEA had teams of experts staying in Iran and others coming in the next two weeks.

"There are a lot of questions that are still on the table and there were a lot of promises made during this trip and now Mr ElBaradei is expecting these promises to be turned into action in the coming days," she said.

Iran insists its nuclear program is geared solely to generating electricity from nuclear reactors.

Iran's often upbeat ambassador to the IAEA Ali Akbar Salehi said both sides were "totally satisfied" with the talks and predicted unspecified "eye-catching developments" soon.

ElBaradei said Rohani had "expressed Iran's willingness to sign the Additional Protocol" on tougher inspections but still had some "apprehensions" about how the protocol would work.

Hard-liners in Iran have said signing the protocol would be tantamount to sanctioning spying on the country. Government officials have voiced concerns that inspectors could visit military or religious sites.

"I made it very clear that all these apprehensions are unfounded. I mean the protocol is never meant in any way to compromise state sovereignty, security, dignity and technology development," ElBaradei said.

ROHANI 'NOT PESSIMISTIC'

Asked by reporters whether Iran was optimistic about signing the protocol, Rohani said: "It will all become clear in the negotiations but of course, I'm not pessimistic."

Rohani said Iran would voice its concerns again at talks with IAEA officials in Tehran starting next week, adding that it was important they were taken into account.

ElBaradei has said that while signing the Additional Protocol would be a positive step by Iran, the IAEA's immediate priority is making sure Iran has provided it with full details on the history and development of its nuclear program to date.

IAEA interest is focused on Iran's sophisticated uranium enrichment facilities which the United States says are at the heart of a clandestine attempt to build an atom bomb.

Iran says it needs to produce low-grade enriched uranium to use as fuel in nuclear power reactors. Highly enriched uranium can be used in nuclear bombs and the IAEA has found traces of it in samples taken at two nuclear sites.

(China Daily October 17, 2003)