VIENNA: Iran, the US and world powers need to do a lot more to reach a deal to save the 2015 nuclear accord, the EU"s political director chairing talks in Vienna said on Tuesday. “Progress made over the last two weeks,” European External Action Service Deputy Secretary General Enrique Mora said on Twitter. “But much more hard work needed. Third expert group was created to address sequencing issues,” he said. Iran"s chief nuclear negotiator warned Tehran would stop the negotiations if faced with “unreasonable demands” or time wasting. “Abbas Araqchi ... assessed the current trend of the talks as going forward, despite the existing difficulties and challenges,” Iranian state media reported. “The Iranian delegation will stop the talks whenever the process of negotiations leads to unreasonable demands, waste of time and irrational bargaining,” Araqchi was quoted as saying