US Secretary of State John Kerry landed in Austria early Sunday to help steer the final stretches of negotiations between global powers and Iran over Tehran's suspect nuclear programme as a deadline for a deal looms.
Buoyed by his success in brokering an end to deadlock over disputed elections in Afghanistan, the top US diplomat arrived from Kabul and was to meet later Sunday with his European counterparts  aiming to wrap up a pact before July 20.
His arrival came as Iran's chief negotiator Abbas Araqchi warned Tehran was ready to walk away if "excessive" Western demands caused the talks to fail.
Eight days before a deadline for a deal, Araqchi said he hoped Kerry's presence as well as other foreign ministers would help overcome remaining "deep differences".
"If we see the excessive demands (of Western powers) persisting and that a deal is impossible, this is not a drama, we will continue with our nuclear programme," Araqchi said.