They were was joined by the head of the Atomic Energy Organization of Iran, Ali Akbar Salehi, and US Energy Secretary Ernest Moniz, who already met earlier on Sunday to discuss the technical issues, Xinhua news agency reported.
Right after his first meeting with Kerry, Zarif flew to Brussels for talks with EU diplomats and his counterparts from Germany, France and Britain on Monday afternoon. He will then return back to Lausanne for further talks with Kerry.
A source close to Zarif said that the top Iranian diplomat seemed to be more confident about reaching a deal.
“Finally, finally we’ll get there,” Zarif was cited as saying when leaving for Brussels, adding that “we need to negotiate with all parties by Friday to see what will be the result in the end”.
“In some issues we are closer to solution. So we can say that solutions are available, but we’re still distant on some issues,” he said.