“I would expect my negotiating partners to refrain from making excessive demands,” Iranian Foreign Minister Mohammad Javad Zarif said during a visit to Athens, adding: “People need to have their foot in reality, not in illusions.”

Zarif also said he was hopeful Iran and world powers would reach a final conclusion on a nuclear deal “within a reasonable period of time”.

Iran, the United States, Britain, France, Germany, Russia and China reached a tentative framework for a nuclear deal on April 2 but several issues remain unresolved. They have a self-imposed June 30 deadline to arrive at a comprehensive agreement.

“If the other side respects what has been agreed in Lausanne and tries to draft based on mutual respect a comprehensive agreement with Iran that is sustainable… then we can meet any deadline,” Zarif said after meeting his Greek counterpart.

“If people insist on excessive demands, on renegotiation, then it will be difficult,” he said. “I am hopeful we will reach a final conclusion within a reasonable period of time.”