Thursday sees a two-pronged diplomatic push to find a nuclear deal with Iran.
First in Tehran with UN nuclear watchdog Yukiya Amano who is hoping to make a breakthrough on the question of access for inspections of military sites.
His visit is being seen as a sign of progress, as world powers have just under a week before the next deadline expires.
Thousands of kilometres away in Vienna, the foreign ministers of France, Germany, Britain, Russia and China are to join the US Secretary of State John Kerry and Iran’s Foreign Minister Javad Zarif who have been in talks since Saturday.
The Western powers want Tehran to scale back its sensitive nuclear activities to prevent it from producing a nuclear weapon. Iran insists its programme is peaceful and wants sanctions lifted.