Iran nuclear negotiations will extend beyond deadline

VIENNA, June 28 (UPI) -- Iranian nuclear negotiations will extend beyond the formal headline established for Tuesday, as Iran's Foreign Minister Mohammed Javad Zarif flies back to Tehran.

Zarif may be flying back to Iran from Vienna, Austria, where the negotiations are taking place, to seek guidance over how much access Iran will grant to nuclear monitors, BBC News reports. Zarif is expected to return Monday, but a long-term extension will not be established.

Negotiators may remain in Vienna for a "few days" beyond the deadline, The Washington Post reported.

Another deadline comes July 10, by which the agreement must be presented to the U.S. Congress for approval, or face a 60-day review. The Obama administration seeks to minimize available time to criticize or demand changes to the deal.

Diplomatic leaders of Iran and the negotiating partners -- the United States, Russia, the United Kingdom, France, Germany and China -- including U.S. Secretary of State and John Kerry and French Foreign minister Laurent Fabius, arrived in Vienna to finalize the deal.

About six addenda remain to be settled, including how Iran's nuclear facilities will be modified and which trade restrictions will be reduced, and negotiators face outside pressure as well.

Supreme Leader of Iran Ayatollah Ali Khamenei said on Wednesday that no commitments will be fulfilled unless sanctions are "lifted immediately" and apparently reeled back from agreements nuclear negotiators have made.

Khamenei has the final authority on all policy and nuclear matters.

Ed Adamczyk contributed to this report.