"Many thanks for the generosity of the dear and courageous people of Iran and its authorities over the past 67 months".
Deputy foreign ministry spokesman Sayyed Abbas Moussawi confirmed Zarif's resignation in an interview with Iran state media IRNA.
However, the US-Iranian relations deteriorated in May 2018 when US President Donald Trump announced his country's decision to withdraw from the JCPOA and reimpose its sanctions on Tehran that had been lifted under the agreement.
This is a breaking story.
According to Reuters, citing Tasnim news agency, some local sources familiar with the matter have confirmed Zarif's resignation, however, it was not immediately clear whether Iranian President Hassan Rouhani would accept it.
This could mark a shift in Iranian foreign policy towards a more hostile, anti-American foreign policy. "If Rouhani does not accept his resignation, if indeed he does not resign, he could come back empowered", Toossi told MEE.
During his tenure, Zarif has appeared frequently on worldwide media outlets to defend Iran's foreign policy and with his fluent English has used his Twitter account to hit out at US President Donald Trump and Prime Minister Benjamin Netanyahu.
Secret backchannel talks between the United States and Iran in Oman became full-fledged negotiations over its nuclear program. He has served as Iran´s foreign minister since August 2013.
Born in 1960, Zarif lived in the USA from the age of 17 as a student in San Francisco and Denver, and subsequently as a diplomat to the United Nations in NY, where he served as Iran's ambassador from 2002 to 2007.