World Bulletin/News Desk

U.S. Secretary of State John Kerry will travel to Vienna later on Thursday to participate in a conference with world powers and Iran on Tehran's nuclear programme, a spokeswoman said.

Iran and six powers, also meeting in the Austrian capital this week, aim to reach a diplomatic agreement by a Nov. 24 deadline to end a 12-year dispute over the Islamic Republic's atomic programme.

"Secretary Kerry will travel from Paris, France to Vienna, Austria, this evening to check in on the Iran nuclear negotiations. His date of departure from Vienna is not yet determined," spokeswoman Jen Psaki said.

The U.N. nuclear agency chief said Iran had failed to provide explanations in response to allegations of possible atomic bomb research and he called on Tehran to step up cooperation with a long-running investigation.