Iranian delegation's intensive talks are still underway at deputy foreign ministers level in Vienna, Trend reports citing IRNA.
Different bilateral and multilateral meetings have so far been held and talks will continue.
Earlier, Iran's top nuclear negotiator Abbas Araghchi said that much legal, technical and political discussion is necessary and talks will be continued.
The talks will continue whenever needed, he added.
The signatories to the nuclear agreement resumed this round of talks on Saturday in a bid to discuss the lifting of US sanctions on Iran and Washington's potential return to the JCPOA. The sixth round of talks is chaired by Enrique Mora, the coordinator of the nuclear deal talks in Vienna.
After the fifth round of talks, Mora declared that he was sure the parties would reach a consensus, but he could not predict the precise time.