The UN nuclear agency expects to reach a deal with Iran enabling it to resume a stalled probe into the country's disputed nuclear programme by next month, the chief UN inspector has said after returning from Tehran.
Even though the International Atomic Energy Agency (IAEA) failed to gain access to the Parchin military complex during Thursday's visit to the Iranian capital, as it had requested, Herman Nackaerts, the head of the delegation, said progress had been made.
"We had good meetings," Nackaerts, the deputy director general of the UN watchdog, told reporters at Vienna airport.
According to Iranian state media on Thursday, Iran's ambassador to the IAEA, Ali Asghar Soltanieh, also said the talks were constructive and good progress had been made.
"Intensive negotiations were held ... There was good progress made. The two sides agreed to hold the next round of talks on January 16 in Tehran," the IRNA news agency quoted him as saying.
The agency believes Iran has conducted explosives tests with possible nuclear applications at Parchin, a sprawling facility southeast of Tehran, and has repeatedly asked for access.
The IAEA wanted an agreement that would enable its inspectors to visit Parchin and other sites that it suspects may be linked to what it has called the "possible military dimensions" to Iran's nuclear programme.
Iran says Parchin is a conventional military site and has dismissed allegations that it has tried to clean up the site before any visit.
Western diplomats say Iran has carried out extensive work at Parchin over the past year - including demolition of buildings and removal of soil - to cleanse it of any traces of illicit activity. The IAEA said a visit to Parchin would still be "useful".
The latest talks were the first between the UN agency and Iran since August, and the outcome could give some indication whether Iran, which denies it wants to develop nuclear weapons, is any more willing to address international concerns over its nuclear programme after US President Barack Obama's re-election last month.
Additional US sanctions
On Thursday, the US imposed more sanctions on seven Iranian companies and five individuals that it said were providing support to Iran's nuclear programme.
The US Treasury Department said the action would bar those companies and individuals from doing business with US firms or citizens, and freeze any assets that they have in the United States.
The IAEA's meetings with Iran are separate from but closely linked to broader efforts by six world powers to resolve the decade-long nuclear dispute.
On Wednesday, senior European Union and Iranian diplomats discussed the timing of possible new talks between Iran and Britain, France, Germany, United States, Russia and China.
The powers want Iran to curb its uranium enrichment program - work which can have both military and civilian purposes - and cooperate fully with the IAEA.
Iran wants sanctions that are severely hurting its oil-dependent economy lifted.