Iranian Foreign Minister Mohammad Javad Zarif has announced his resignation on his Instagram page.
"Thank you very much to the dear and honorable people of Iran over the past 67 months. I sincerely apologize for the incapacity to continue serving and all the shortcomings during the service. I thank the Iranian nation and officials," he wrote on his Instagram page.
Zarif has served as Iran's top diplomat since August 2013, when he replaced Ali Akbar Salehi, the current head of the Atomic Organization of Iran.
As foreign minister, Zarif led the Iranian negotiations team with the P5+1 countries -- the United States, Russia, China, Britain, France, and Germany -- which produced on 14 July 2015 the landmark 2015 nuclear agreement known as the Joint Comprehensive Plan of Action on 14 July 2015.
Under the deal, Iran pledged to curb its nuclear activities in return for the lifting of international economic sanctions.
Based on reporting by Reuters and AFP