Iran's supreme leader Ayatollah Ali Khamenei reiterated on Wednesday his country's "red lines" in negotiations with world powers over its controversial nuclear program due to resume next week in Vienna.
Khamenei's intervention came as both the United States and EU confirmed that U.S. Secretary of State John Kerry and EU foreign policy chief Catherine Ashton would meet in the Austrian capital with Iranian Foreign Minister Mohammad Javad Zarif.
Ashton will first hold bilateral talks next Tuesday with Zarif, as is customary ahead of each round of nuclear negotiations, and a three-way meeting is to be held the next day on October 15, her spokesman Michael Mann said.
Top-level U.S. diplomats would also meet with their Iranian and EU counterparts on Oct. 14 ahead of the trilateral ministerial talks, a U.S. official said, also confirming the trilateral talks.
"Our focus... is determining whether it's possible to reach an agreement by November 24 that effectively closes down Iran's pathways to nuclear materials for a nuclear weapon," State Department spokeswoman Jen Psaki told reporters.
U.S. officials "continue to believe that there is still adequate time to work through these issues and arrive at a comprehensive agreement that will give the international community assurances that Iran will not acquire a nuclear weapon," she added.
After failing to reach an initial July deadline, Iran and the P5+1 group of nations -- China, the United States, France, Britain, Russia and Germany -- have set November 24 as the date to strike a deal guaranteeing that Tehran's nuclear program is used for exclusively peaceful means.
But talks have stalled over the issue of Iran's future capacity for uranium enrichment and the timetable for the lifting of international sanctions against Tehran.
"We still don't have an understanding of the major issues, so that's what the purpose of the discussion is," Psaki said, adding there would be "many more meetings" including at expert level as they seek to hammer out a deal.
An info-graphic published on Khamenei's official website outlined 11 points to be observed by negotiators before Iran will sign an accord.
Khamenei red lines info-graphic