"The second series of discussions that started on Monday ended after three days and there will be a new set of discussions in the next ten days," said Iran's ambassador to the International Atomic Energy Agency (IAEA), Ali Asghar Soltanieh, according to the Mehr news agency.
The IAEA has said the talks, which began on April 21, are focused on pressing Iran over allegations that it conducted studies on how to design a nuclear weapon.
Iran insists that the talks are merely routine cooperation between the authorities and the agency, however.
Soltanieh made no mention of an agreement announced by the IAEA after the first round that Iran would answer the allegations during May and instead said the latest meetings were in line with a more general accord from August 2007.
"Iran responded to all the ambiguities mentioned by the IAEA in line with the agreement (of August 2007) and is ready to respond to all the questions and ambiguities as part of its cooperation with the agency, just like any state," he said.
The latest talks involved Soltanieh and other top officials from Iran's atomic energy organisation.
The IAEA was represented by its deputy director general Olli Heinonen who reportedly left late on Monday while other officials remained to continue the discussions.
The so called "weaponisation studies" stem from intelligence provided to the IAEA by some member states.
In a closed-door briefing to diplomats at IAEA headquarters in Vienna on February 25, Heinonen presented detailed information suggesting that Iran could have been studying how to use its nuclear technology to make a warhead.
Iran, which insists that its nuclear programme is entirely peaceful and aimed solely at generating energy, furiously denounced the presentation as fake.
