US Secretary of State John Kerry signs a series of documents, including the certification to the US government that International Atomic Energy Agency (IAEA) had certified Iran's compliance in their report and waivers to implement the lifting of the US Congressional nuclear-related sanctions as outlined in the Joint Comprehensive Plan of Action (JCPOA), in Vienna January 16, 2016. [Photo/Agencies]

　　US Secretary of State John Kerry talks with Iranian Foreign Minister Javad Zarif after the International Atomic Energy Agency (IAEA) verified that Iran has met all conditions under the nuclear deal, in Vienna January 16, 2016. [Photo/Agencies]