The head of the UN’s nuclear watchdog said on Wednesday that efforts to get Iran to co-operate with inspectors were not bearing fruit.
Director General Rafael Grossi reported “no progress” to the board of the International Atomic Energy Agency at the start of a three-day meeting in Vienna.
He said inspectors were in the dark about a “mass of activity” in Iran because cameras and monitoring equipment were disconnected.
It came as Iran said there was no plan for the IAEA to visit Tehran to resolve issues linked to unexplained nuclear traces.
Mr Grossi said the IAEA cannot be sure that Iran’s nuclear activities are peaceful until those issues are resolved.
But he said at a press conference after Wednesday’s meeting that he could not force Iran to co-operate.
“It’s their obligation to provide us with information we need and we are trying to find ways and mechanisms. We have been trying to do this for many, many months,” he said.
“So far, we haven’t been very successful.”
Tehran denies any ambition to develop a nuclear weapon, but in a report to the board on Wednesday, Mr Grossi described increased uranium enrichment by Iran to the level of 60 per cent.
Mr Grossi said large amounts of data were missing in Iran because IAEA cameras and monitoring equipment had been switched off.
“There is a mass of activity about which we don’t know anything,” he said.
Iran has openly flouted its promises to limit enrichment since the US pulled out of the 2015 nuclear deal four years ago.
Talks to revive that deal are at an impasse, with the US saying this week that the pact was not a priority.
“Our focus is not an accord that isn't moving forward, but what is happening in Iran,” Washington’s special envoy for Iran Robert Malley said on Monday.
The US has rejected what it calls unacceptable Iranian attempts to link the deal to the end of the IAEA’s investigation.
Mr Grossi told the 35-member board he had “serious concern that there has been no progress in clarifying and resolving the outstanding safeguard issues during this reporting period”.
“They need to be resolved for the agency to be in a position to provide assurance that Iran’s nuclear programme is exclusively peaceful,” he said.