Zarif made the remarks following a six-hour long trilateral meeting with European Union foreign policy chief Catherine Ashton and US Secretary of State John Kerry in the Austrian capital, Vienna.
Zarif, who heads the Iranian negotiating team in nuclear talks with the six countries, also described the trilateral talks as “very difficult”, but said progress was made and possible solutions discussed.
“It was very difficult, serious and intensive … but instead of focusing on problems, we discussed solutions as well,” Zarif said. “There was progress in all the fields.”
Zarif also told online news site al-Monitor that the gaps were “narrowing, but we still have a long way to go.”
“It is reconcilable, provided everyone makes the tough decisions,” he said.
Tehran and the six major world powers – the United States, France, Britain, China, Russia and Germany – have started a fresh round of negotiations on Tehran’s nuclear energy program in Vienna on Thursday.
Zarif and Ashton jointly lead the negotiations, which will center on outstanding issues related to Tehran’s nuclear program.
Iran and its negotiating partners are currently working to reach a final agreement aimed at ending the longstanding dispute over Tehran’s civilian nuclear work as a November 24 deadline approaches.
Last November, the two sides clinched an interim nuclear accord, which took effect on January 20 and expired six months later. However, they agreed to extend their talks until November 24, as they remained split on a number of key issues.