Secretary of State John Kerry is holding a series of meetings with U.S. partners in the nuclear talks before an evening negotiating round with the Iranians.

Kerry was meeting British Foreign Secretary Philip Hammond in a Vienna hotel as world powers seek progress in the talks. He'll later talk to chief European Union diplomat Federica Mogherini and Chinese Foreign Minister Wang Yi.

Thursday evening will be dominated by Kerry's scheduled session with Iranian Foreign Minister Mohammad Javad Zarif.

The talks already are two days past a June 30 deadline for a final deal curbing Iran's nuclear program for a decade in exchange for sanctions relief.

The seven nations in the talks have agreed to continue negotiating until at least July 7.