The deadline for Iran nuclear deal has been extended until June 30, 2015, after talks in Vienna failed to reach a comprehensive agreement.

Six world powers want Iran to curb its nuclear program in return for the lifting of sanctions.

Tehran says it is not seeking nuclear weapons, but wants atomic energy.

The six countries – the US, UK, Russia, China, France and Germany – have been in negotiations with Iran to finalize a preliminary deal reached last year in Geneva.

Iran would be allowed to continue accessing $700 million per month in frozen assets during that period.

Diplomats expect to reach a political agreement by March 1, 2015, with the full technical details of the agreement confirmed by July 1, 2015.

Iranian President Hassan Rouhani is to give a national address this evening, Iranian news agencies reported.

There are thought to have been three key sticking points in the negotiations:

• Western states want to reduce Iran’s capacity for uranium enrichment in order to prevent it acquiring weapons-grade material but Tehran is set on expanding it nearly twentyfold in the coming years
• Iran wants sanctions lifted immediately but Western states want to stagger their removal to ensure Tehran abides by its commitments
• Iran has failed to explain explosives tests and other activity that could be linked to a nuclear weapons program and has denied international nuclear inspectors access to its Parchin military site

Highly enriched uranium can be used to make a nuclear bomb, but uranium enriched to lower levels can be used for energy purposes.

Under the terms of international treaties, countries have the right to develop nuclear energy, which Iran insists is its only aim.

However, the International Atomic Energy Agency (IAEA) says it has been unable to confirm Tehran’s assertions that its nuclear activities are exclusively for peaceful purposes.

The UN Security Council has adopted six resolutions since 2006 requiring Iran to stop enriching uranium, with sanctions to persuade Iran to comply.

The US and EU have imposed additional sanctions on Iranian oil exports and banks since 2012, hitting Iran’s oil revenue badly.

Both Saudi Arabia and Israel are also vehemently opposed to Iran acquiring nuclear weapons. Saudi Foreign Minister Prince Saud al-Faisal visited Vienna at the weekend for talks with US Secretary of State John Kerry, though his country is not formally involved in the discussions.

[youtube n1aqmGBff1E 650]