US Secretary of State John Kerry will meet Saudi Foreign Minister Saud al-Faisal today to "update" him on the nuclear negotiations between Iran and six world powers in Vienna, a US official said.

The official did not give details about the meeting. Saudi Arabia, a close US ally is worried about the implications of any rapprochement between Washington and Tehran. 

The parties have been holding talks in Vienna over the past six days to hammer out a comprehensive deal on Tehran’s nuclear energy program. Diplomats say the two sides have made progress but big gaps still remain.

Last November, Iran and the P5+1 – Russia, China, France, Britain, the US and Germany -- clinched an interim nuclear accord that took effect on January 20 and expired six months later. They agreed to extend their talks until November 24 as they remained divided on a number of key issues.

Sources close to the Iranian negotiating team say the main stumbling block in the way of resolving the Western dispute over Iran’s nuclear energy program remains to be the removal of all the bans imposed on the country, and not the number of centrifuges or the level of uranium enrichment.

Tehran wants the sanctions entirely lifted while Washington, under pressure from the pro-Israeli lobby, insists that at least the UN-imposed sanctions should remain in place.