2015 nuclear deal

The election of a cleric with allegiance to Iran's supreme leader will pose unique challenges for the Biden administration — most notably, when it comes to the Iran nuclear deal.

The Japanese prime minister has offered to try to calm nerves between Washington and Tehran amid rising tensions that have followed the U.S. withdrawal from the 2015 nuclear deal.

Mohammad Javad Zarif was an architect of the Iran nuclear deal. His announcement provides no explanation for his immediate departure.