Negotiations seeking a definitive accord on Iran's nuclear programme will resume on May 12 in Vienna, the European Union and Tehran said Tuesday.

EU negotiator Helga Schmid and her Iranian counterparts Abbas Araghchi and Majid Takht Ravanchi "will resume their work on 12 May in Vienna," the EU diplomatic service said in a statement.

The political leaders of the other world powers involved in the negotiations will join the talks on May 15, the statement said.

Iran's Deputy Foreign Minister  Abbas Araghchi, speaking on state television in Tehran, confirmed the plans.

"We will resume negotiations next Tuesday up to Friday when the G5+1 (global powers) will join us and we will arrive at some conclusions," said Araghchi, who is part of an Iranian tean currently taking part in expert-level talks in New York, on the  margins of a UN disarmament summit.

Iran and the G5+1  -- the five permanent members of the UN Security Council plus Germany  -- want to turn a framework accord reached in Switzerland on April 2 into a full agreement by June 30.

US top diplomat John Kerry met his Iranian counterpart Mohammad Javad Zarif in New York on Monday hoping to push forward the tough nuclear negotiations as they reach the final phase.

Lower-level negotiations resumed last week in Vienna after the April 2 breakthrough in Lausanne, but little has trickled out about the discussions.

Under the agreed parameters, Iran, which denies seeking the atomic bomb, is set to scale down its nuclear programme for 10 to 15 years or more, and allow closer UN inspections.

The exact details of how this will work, in particular the scale and timeframe under which the powers will lift painful sanctions slapped on the Islamic republic, still need to be nailed down.