The head of the International Atomic Energy Agency (IAEA) says the body is still waiting for Tehran to provide answers for questions about Iran’s nuclear programme. “We are at a very difficult juncture at the moment,” general director Rafael Grossi said at the Davos World Economic Forum (WEF) on Wednesday. After discovering uranium particles outside of known nuclear facilities in Iran, the IAEA in Vienna has been trying for years to find out whether these traces come from secret nuclear projects and stockpiles. In March, the organization agreed a plan with Iran, with Tehran supposed to provide…