GENEVA, Nov. 10 (Xinhua) — The European Union foreign policy chief said early Sunday that world powers and Iran would reconvene talks over its controversial nuclear program on Nov. 20.

After three-day talks between the five permanent members of the United Nations Security Council – Britain, China, FranceRussia and the United States plus Germany, and Iran, with the involvement of foreign ministers, the two sides failed to nail down an interim deal as expected.

EU High Representative for Foreign Affairs and Security Policy Catherine Ashton told reporters that “some differences remain.”