VIENNA, Jan. 18 (Xinhua) -- The International Atomic Energy Agency (IAEA) has failed to reach an agreement with Iranian authorities on the investigation of the latter's disputed nuclear program, UN nuclear inspectors said here on Friday.
"Differences remain, so we could not finalize the structured approach to resolve the outstanding issues regarding possible military dimension of Iran's nuclear program," IAEA deputy director general Herman Nackaerts told Xinhua at the Vienna airport.
A new round of talks would be held on February 12 in Tehran, Nackaerts said.
Iran and the West are locked in a bitter dispute over the former's nuclear ambitions, with the latter accusing Tehran of developing nuclear weapon under cover of its peaceful purpose nuclear program, a charge Iran has consistently denied.
The IAEA, whose mission is to prevent the spread of nuclear weapons, has been trying for a year to negotiate the so-called structured approach with Iran giving the inspectors access to sites, officials and documents for their long-stalled inquiry.
Some hint of optimism was in the air after Nackaerts expressed his confidence to clinch a deal soon with Tehran over the structured approach following previous talks with Iran in December 2012.
Before leaving for Tehran earlier this week, Nackaerts said he was confident an agreement could be finalized at next Wednesday's talks and that access to Parchin would be part of it.
But the two-day talks again disappointed the IAEA - IAEA inspectors were still not allowed to visit the Parchin military site where it the Vienna-based UN nuclear watchdog believes explosives tests relevant for nuclear weapons development may have taken place.
Access to Parchin, however, is not the only outstanding obstacle. Iran has long insisted that no country would allow foreign inspectors to visit its military sites repeatedly.
Furthermore, Western countries' feeding of intelligences to the IAEA as "evidences" of possible military dimensions of Iran's nuclear program has also irked Tehran, which asked the agency to show these confidential intelligence to Tehran.
The fail of the IAEA-Iran talks also dimmed the future negotiations between Iran and P5+1 countries, including Britain, China, France, Russia, U.S. plus Germany, which are supposed to resume soon.
The negotiation has already been held back by deep-rooted differences, with Iran demanding the West to dismantle tough sanctions that have made it hard for Tehran to sell its crude in the global market.
The West, meanwhile, wants Tehran to give up its nuclear program which Iran has insisted to be peaceful and legitimate. The great progress Iran made on uranium enrichment in the year 2012 was widely recognized as both the counterattack against the West's crippling policy, and its bargaining chips on the negotiation table.