"You are tasked with overseeing major national and international developments as well as how far we succeed in achieving the goals of the constitution," Pezeshkian said in a letter of appointment carried by the official IRNA news agency.

Foreign minister between 2013 and 2021 in the government of moderate president Hassan Rouhani, Zarif became a familiar figure on the international stage during the lengthy negotiations for the 2015 accord.

The deal was effectively torpedoed three years later when then president Donald Trump pulled the United States out of the deal and reimposed crippling US sanctions which he required allies to respect.

But it made Zarif a figurehead for the more open, outward-looking Iran that Pezeshkian pledged to strive for during his campaign, in which he was frequently joined by the former top diplomat.