TEHRAN, Nov 1 (Reuters) Iran and the UN nuclear watchdog ended a crucial round of talks today meant to help clear up suspicions about Tehran's atomic activities, the official IRNA news agency said. It gave no details.
The session, which began on Monday, ended a day before world powers were due to meet in London to discuss a possible third round of UN sanctions against Iran over its refusal to halt work the West fears is aimed at making nuclear bombs.
IRNA said official sources had not yet commented on the latest round of negotiations, attended by International Atomic Energy Agency deputy director Olli Heinonen. Iran says its nuclear programme is only aimed at generating energy.
After stonewalling the UN agency for years, Iran pledged in August to answer questions about past secret aspects of its programme by the end of 2007 in the hope of warding off tougher UN sanctions.
The United States, saying the deal failed to address the core UN demand that Tehran suspend work that could be used for making bombs, is pushing for tougher UN sanctions to step up pressure on the Middle East country.
A senior US official said in Vienna today that Russia and China had been blocking further UN sanctions against Iran for months and pledged a drive to impose them if Iran did not halt nuclear activity within two weeks.
The IAEA has withheld comment on whether Iran, in a series of talks since August, has been resolving the issues of transparency one by one as promised. An IAEA report is due in mid-November.
This week's talks covered questions about Iran's development of centrifuges used to enrich uranium -- the third and last session scheduled to deal with the subject.
Iran uses a breakdown-prone 1970s vintage of centrifuge, called the ''P-1''. It is researching an advanced P-2 model able to refine uranium much faster, using less energy, at sites off limits to IAEA inspectors.
Refined uranium can be used to fuel power plants but can also, if enriched further, provide material for nuclear bombs.
Iran says it aims to generate electricity so that it can export more of its valuable oil and gas.
The IAEA says answers to the questions would help it judge whether Iran's activity is wholly peaceful or not. Among questions yet to be addressed are over possible experiments linking uranium processing and missile warhead designs.
Reuters AM GC2247