World powers are struggling to reach a provisional deal with Iran to limit its nuclear programme.
As talks in Geneva moved into a third day, Iran insisted it would not sign an agreement that did not have specific guarantees of its right to enrich uranium.
Iran’s deputy foreign minister, Abbas Araqchi, said: “We are working on narrowing the gaps but the gaps are still there.”
Enriched uranium is a critical component both in nuclear power generation and nuclear weapons.
