US Secretary of State John Kerry (L) speaks with Iranian Foreign Minister Mohammad Javad Zarif after the International Atomic Energy Agency (IAEA) verified that Iran has met all conditions under the nuclear deal during the E3/EU+3 and Iran talks in Vienna on January 16, 2016.
The historic nuclear accord between Iran and major powers entered into force as the UN confirmed that Tehran has shrunk its atomic programme and as painful sanctions were lifted on the Islamic republic. / AFP / POOL / KEVIN LAMARQUE        (Photo credit should read KEVIN LAMARQUE/AFP/Getty Images)