Iranian Foreign Minister Mohammad Javad Zarif (2nd L) shakes hands with US Secretary of State John Kerry next to Chinese Foreign Minister Wang Yi (far L) and French Foreign Minister Laurent Fabius (far R) after a statement on early November 24, 2013 in Geneva. World powers on November 24 agreed a landmark deal with Iran halting parts of its nuclear programme in what US President Barack Obama called "an important first step". According to details of the accord agreed in Geneva provided by the White House, Iran has committed to halt uranium enrichment above purities of five percent. AFP PHOTO / FABRICE COFFRINI        (Photo credit should read FABRICE COFFRINI/AFP/Getty Images)