Iranian Foreign Minister Mohammed Javad Zarif left nuclear talks in Vienna on Sunday, after it appeared that negotiations would miss a Tuesday deadline. A senior U.S. official acknowledged that talks would likely miss their June 30 deadline, the AP reports. Zarif reportedly returned to Tehran to seek a final bargaining position after weeks of talks with officials from the U.K., U.S., France and Germany. U.S. Secretary of State John Kerry is expected to stay in Europe until Zarif's return on Tuesday while the European ministers were planning to return to their countries. Among the differences in finalizing a deal was how much access Iran should give to the UN group monitoring nuclear restrictions.