Updated

A semiofficial news agency is reporting that senior investigators from the U.N. nuclear watchdog have ended two days of talks with Iranian officials over allegations the Islamic Republic may have carried out tests on triggers for atomic weapons.

Fars news agency says the two sides agreed to hold another round of negotiations on Feb. 12.

Fars didn't say if any progress was made, but a senior diplomat from an International Atomic Energy Agency member state in Vienna said shortly before talks ended that they were "not going well." He demanded anonymity because he was not authorized to divulge confidential information.

U.N. team leader Herman Nackaerts had hoped the IAEA would be able to "finalize the structured approach" that would outline what the agency can and cannot do in its investigation.