"Tomorrow is the start of a difficult and relatively time-consuming way forward. I am hopeful that by Wednesday we can reach agreement on a roadmap to find a path toward resolution."

Mohammad Javad Zarif, Iranian foreign minister and chief nuclear negotiator

"When President (Barack) Obama says that he will not allow a nuclear-armed Iran, he means what he says. I believe firmly that no deal is better than a bad deal."

John Kerry, US secretary of state

"We continue to believe that while there is a significant chance of a deal by the end of the second quarter of 2014, an agreement on balance remains improbable."

Cliff Kupchan, Middle East analyst of risk consultancy Eurasia group

(China Daily 10/15/2013 page12)