VIENNA - The U.N. nuclear agency reported deadlock Thursday in its probe of allegations that Iran worked on atomic arms - an assessment that further dims hopes that Tehran and six world powers could negotiate a full nuclear deal by their June deadline.
The U.S. and five other powers insist that Tehran must fully cooperate with the U.N.'s International Atomic Energy Agency's probe for any nuclear agreement that grants Iran total sanctions relief.
"Iran has not provided any explanations" on the suspicions, according to a confidential report obtained by The Associated Press.
The agency also said that Iran is honoring commitments to put temporary restraints on its atomic activities as it negotiates on the long-term nuclear deal.
Iran agreed a year ago to work with the IAEA. But like previous probes, the investigation quickly stalled over Tehran's insistence that it never wanted or worked on such weapons and any evidence to the contrary is fabricated.
Diplomats have told the AP that Washington is willing to extend the IAEA investigation, if an agreement is reached by June that constrains Iran's uranium enrichment program and other activities that could be turned to making nuclear arms.
They say the U.S. would set a time limit on such an extension and keep some sanctions on Tehran in place until the IAEA delivers its ruling.
That, however, would satisfy neither hardliners in Iran who want a full lifting of sanctions, nor critics in the U.S. Congress worried that any deal would fall short of seriously crimping Iran's ability to make nuclear arms.
With Tehran showing no signs that it is ready to cooperate, the international community might have to settle longer term for an IAEA assessment based only on American, Israeli and other intelligence and its own information gathering.
A senior diplomat said IAEA chief Yukiya Amano planned to meet next week with Iranian Deputy Foreign Minister Abbas Araghchi in hopes of advancing the talks. He demanded anonymity because he is not authorized to divulge the information.