TOPSHOT-SWITZERLAND-IRAN-US-NUCLEAR-POLITICS

TOPSHOT - Iran's Foreign Minister Mohammad Javad Zarif (C on left) and head of the Atomic Energy Organization of Iran Ali Akbar Salehi (C on right) talk outside with aides after a morning negotiation session with U.S. Secretary of State John Kerry over Iran's nuclear programme in Lausanne March 19, 2015. US and Iranian negotiators entered into a fourth day of tough talks towards a landmark nuclear deal, with Tehran's foreign minister talking down prospects for a breakthrough this week. US Secretary of State John Kerry and his Iranian counterpart have been haggling in Switzerland since Monday as they seek to agree the outlines of this potentially historic agreement by March 31. AFP PHOTO / POOL / Brian Snyder (Photo by BRIAN SNYDER / POOL / AFP) (Photo by BRIAN SNYDER/POOL/AFP via Getty Images)