Iranian Foreign Minister Mohammad Javad Zarif and European Union foreign policy chief Catherine Ashton made the announcement at a joint press conference on Friday after extensive negotiations between the two sides continued in the Austrian capital Vienna.
The original deadline for a comprehensive deal between the two sides was due to expire on Sunday.
“We have made tangible process on some of the issues,” a joint statement said, adding that there were still “significant gaps on some core issues, which will require more time and effort.”
The statement said a new round of negotiations will kick off in the “coming weeks.”
US Secretary of State John Kerry said at a different presser in Vienna that 2.8 billion dollars of Iranian funds will be unfrozen during the new round of talks.
Iran and the five permanent members of the United Nations Security Council – China, Russia, Britain, France and the United States – plus Germany clinched a landmark interim deal in Geneva on November 24, 2013.
Under the deal, dubbed the Geneva Joint Plan of Action, the six countries undertook to provide Iran with some sanctions relief in exchange for Iran agreeing to limit certain aspects of its nuclear activities during a six-month period. It was also agreed that no nuclear-related sanctions will be imposed on Iran within the same timeframe. The agreement took effect on January 20.