Senior U.N. nuclear inspectors and Iran ended two days of talks in Tehran on Thursday with no early sign of any breakthrough in unblocking their investigation into suspected atomic bomb research in the Islamic state.

Iran’s ISNA and Fars news agencies reported that a further meeting between the International Atomic Energy Agency (IAEA) and Iran would be held on Feb. 12 in the Iranian capital, but gave no details.

The Vienna-based U.N. agency had hoped to finalise an elusive framework deal with Iran this week that would allow the IAEA to resume a long-stalled inquiry into suspected military dimensions to the country’s nuclear programme.

Diplomats in Vienna said they did not yet have details on how the talks in the Iranian capital had ended, but made clear they were not optimistic that an agreement had been struck.

The IAEA team led by Deputy Director General Herman Nackaerts was due to return to Vienna early on Friday, a diplomatic source said. There was no immediate comment from the U.N. agency.

The IAEA, whose mission is to prevent the spread of nuclear weapons, has been trying for a year to negotiate a so-called structured approach with Iran giving the inspectors access to sites, officials and documents for their long-stalled inquiry.

(Reuters)