- US urges Iranians to stick to Lausanne guidelines
- Both sides rule out chance of reaching agreement by midnight
- Sticking points on inspections, sanctions removal remain
Nuclear talks between Iran and the P5+1 group of world powers are widely expected to continue past the 30 June deadline, as Irans foreign minister rejoins the negotiations in Vienna.
In its background briefing in Vienna on 29 June, the US Department of State said the parties are planning to remain in Vienna past 30 June to keep negotiating.
We are still very focused on concluding a comprehensive agreement in this negotiating round, and no one is talking about a long-term extension; no one, said a senior official from the department.
Iran and the P5+1 world powers the US, the UK, France, Germany, China and Russia are aiming to reach a deal to give Tehran relief from sanctions in exchange for limiting the development of its nuclear programme.
Negotiations in Lausanne, Switzerland, to reach a framework agreement earlier in the year overran by two days before a deal was ironed out on 2 April.
Irans Foreign Minister Mohammad Zarif returned to the talks in Vienna after flying back to Iran to consult government officials.
Zarif returned with the countrys nuclear chief Ali Salehi and Hossein Fereidoun brother and special adviser to President Hassan Rouhani.
Negotiators had initially planned to complete the agreement by midnight, but officials from both sides have acknowledged they will need more time.
The terms currently under negotiation are thought to be significantly more detailed than the framework agreement signed on 2 April.
Irans Supreme Leader Ali Khamenei cast doubts on negotiations when, in a speech last week, he appeared to go back on some of the concessions agreed in the interim deal.
His ultimatum ruled out the long-term freeze on Iranian nuclear research and development, and the demands for UN inspections of military sites where nuclear development is thought to have taken place.
Khamenei also demanded that sanctions be removed immediately after an agreement, while the P5+1 group has called for more sanctions to be lifted as the UN completes its inspections of nuclear sites.
The US Department of State and officials from other P5+1 countries have urged Iranian negotiators to stick to the parameters agreed in Lausanne.
Washington released a fact sheet after the framework agreement, claiming Iran had agreed to all the parameters on the document. However, Tehran quickly disputed that it had agreed to the gradual removal of sanctions, asserting that sanctions must be immediately lifted.
If a deal is reached, the removal of sanctions is expected to bring significant benefits to the Iranian economy, with the immediate gains including an increase in oil production and exports, and a payout of more than $100bn in frozen overseas oil funds.