US Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif in Geneva ahead of nuclear discussions in January (Photo: AP)

(VOVworld)- US Secretary of State John Kerry will visit Europe this weekend to meet with Iranian Foreign Minister Mohammad Javad Zarif.

Their talk, scheduled for Saturday in Geneva, is considered a decisive factor in reaching a historic nuclear accord with Tehran.

State Department spokesman Jeff Rathke said the talk aims to make progress towards a comprehensive deal ahead of the end-of-June deadline and narrow the current gap of differences.

On Thursday, Zarif warned its negotiating partners not to make “excessive demands”.

After talks in Athens with Greek Foreign Minister Euclid Tsakalotos, Zarif said an agreement with negotiators from the US, Russia, China, Britain, France, and Germany is possible if the parties involved “have their foot in reality, not in illusions.”

French Foreign Minister Laurient Fabius said Wednesday that Paris will oppose a final nuclear deal with Iran unless Tehran allows UN inspections of all of its nuclear facilities including military bases.