Kerry to join Iran nuclear talks

EU foreign policy chief Catherine Ashton, second left, is leading the talks

US Secretary of State John Kerry is heading to Geneva to help negotiate a nuclear deal with Iran.

He will join foreign ministers from Russia and Iran, and officials from other world powers.

They are aiming to find a deal that would see Iran curb uranium enrichment in return for a loosening of sanctions.

However, US politicians have indicated they will push forward with a bill proposing more sanctions against Iran next month if the talks fail.

Talks extended?

Negotiators have been working since Wednesday to try to find an agreement which is acceptable to Iran and its negotiating partners known as the P5+1 - the US, Russia, China, France, Britain and Germany.

The talks had been scheduled to conclude on Friday, but they now look likely to continue into the weekend.

EU foreign policy chief Baroness Catherine Ashton is leading the conference, and on Friday she met briefly with Iranian Foreign Minister Mohammed Javad Zarif, for a conversation which Iran's official Irna news agency described as "complicated and tough".

Iran insists its nuclear programme is for peaceful purposes, but some world powers suspect it is seeking a nuclear weapons capability.