Talks between Iran, world powers on nuclear issue to resume Sept. 18 in New York

EU spokesman Michael Mann said Thursday that preparatory meetings will be held in Vienna next week. Negotiators face a Nov. 24 deadline to overcome stubborn differences over the size and capacity of activities by Tehran that could be used to make nuclear arms.

EU foreign policy chief Catherine Ashton is coordinating the talks on behalf of the U.S., Russia, China, Britain, France and Germany.

The talks have stalled over intense disagreements over the purpose of Iran’s nuclear program, which Tehran says is aimed at peaceful purposes only.