Iranian Foreign Minister Mohammad Javad Zarif heading a delegation left Tehran for China on Monday.
He also flew to Biarritz urgently earlier on Sunday to hold talks with French President Emmanuel Macron and Foreign Minister Jean Yves Le Drian to discuss with leaders of the states parties to the Joint Comprehensive Plan of Action on how to salvage the landmark international agreement.
The Iranian diplomat made a surprise visit to France to meet leaders of G-7 industrialized countries except for the United States in the French city of Biarritz.
After China, Zarif is to visit Japan and Malaysia to pursue Islamic Republic of Iran's active diplomacy.
Meanwhile, Iranian foreign minister wrote in his Twitter account: "Iran's active diplomacy in pursuit of constructive engagement continues."
He added: "Road ahead is difficult. But worth trying."
Zarif had earlier visited Finland, Norway, Sweden and France.