Speaking to reporters, Qun added that both sides are keen and there is a friendly atmosphere in the talks.
The Chinese diplomat noted that the process of drafting the text of the final agreement started from the previous round of negotiations in Vienna.
He said all the parties are working hard, aiming at reaching an agreement until July 20.
He emphasized that nothing is agreed untill all the points are agreed upon.
Qun continued that there might be consensus on some points, but unless not all the points are agreed, the parties cannot claim they have reached a comprehensive solution.
The five-day negotiations are aimed at drafting a comprehensive deal to resolve the decade-long standoff over Tehran's peaceful nuclear energy program.
Iran and the six world powers inked an interim deal on Tehran’s nuclear program in Geneva last November, which came into force on January 20. The interim deal until July 20, the parties will draw up a comprehensive nuclear deal which will lead to a lifting of all anti- Iran sanctions which had been imposed on Tehran by US and EU as well as UN Security Council.