Iranian soldiers chant anti-Israeli and anti-US slogans during a ceremony marking the 36th anniversary of the return from exile of the founder of Iran's Islamic Republic, Ayatollah Ruhollah Khomeini on February 1, 2015 at Khomeini's mausoleum in a suburb of Tehran. Khomeini returned from exile in 1979, the trigger for a revolution which spawned an Islamic state now engulfed in a deep political crisis. AFP PHOTO/ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images)
US Secretary of State John Kerry (L) and Iran's Foreign Minister Mohammad Javad Zarif attend a bilateral meeting in Vienna, Austria, May 17, 2016.
/ AFP / POOL / LEONHARD FOEGER (Photo credit should read LEONHARD FOEGER/AFP/Getty Images)
TAMPA, FL - MARCH 14: Republican presidential candidate Donald Trump speaks to supporters during a town hall meeting on March 14, 2016 at the Tampa Convention Center in Tampa , Florida. Trump is campaigning ahead of the Florida primary on March 15. (Photo by Brian Blanco/Getty Images)
