The three-day constructive negotiations between Iran and a delegation from the International Atomic Energy Agency (IAEA) ended in Tehran on Tuesday, Jan 31.

According to Fars News Agency, the two sides agreed to continue talks while media reports said that negotiations were held in a "positive and constructive" atmosphere.

Iranian Foreign Minister Ali Akbar Salehi said on Monday that the IAEA team could extend the visit and inspect Iran's nuclear sites, but the team announced that they would leave Iran later on Tuesday.

The six-member delegation of the IAEA headed by Herman Nackaerts, the deputy director-general and Rafael Grossi, the assistant director-general for policy arrived in Tehran on Sunday.

The visit came at the invitation of the Atomic Energy Organization of Iran (AEOI).

Nackaerts told reporters as he was about to depart from Vienna airport that the team will try to resolve all the outstanding issues with Iran.

According to AFP, upon his return Wednesday, the chief UN nuclear inspector said that there was "still a lot of work to do" with Iran over its contested atomic program.

"We are committed to resolving all the outstanding issues and the Iranians said they are committed too. But of course there is still a lot of work to be done, and so we have planned another trip in the very near future," Nackaerts told reporters at Vienna airport.