VIENNA –  U.S. Secretary of State John Kerry has arrived in Vienna for a new round of nuclear talks with Iran.

The negotiations are happening only days away from a deadline for a comprehensive pact preventing Tehran from developing nuclear weapons.

However, world powers and Iran appear set to extend the deadline and allow more time for negotiation.

Britain, France and Germany have sent their foreign ministers to Austria’s capital for talks over the next couple of days, as has Iran.

But the top diplomats from China and Russia aren’t even bothering to show up, sending lower-ranking officials instead.