The European Union's foreign policy chief has arrived in Iran, her first visit to the Islamic Republic as nuclear talks with world powers continue.

Catherine Ashton leads the six-nation group - the US, Britain, France, Russia, China and Germany - in talks with Iran over Tehran's nuclear programme. Iranian media said the visit signals the normalisation of Iran's relations with Europe after eight years of tension.

Iran struck an initial deal on November 24 to curb its nuclear programme. Negotiations for a final deal are ongoing.