PRAGUE (Reuters) - U.S. Secretary of State John Kerry will travel to Vienna this weekend to assess Iran's willingness to take the measures necessary if six world powers and Tehran are to reach a deal that would end sanctions in return for curbs on the Iranian nuclear programme, the State Department said on Thursday.
"The Secretary will gauge the extent of Iran's willingness to commit to credible and verifiable steps that would back up its public statements about the peaceful nature of its nuclear programme," State Department deputy spokeswoman Marie Harf said in a statement.
"The Secretary will see if progress can be made on the issues where significant gaps remain and assess Iran's willingness to make a set of critical choices at the negotiating table," she added. The six powers have a July 20 deadline for a deal, although an extension is theoretically possible.
Schedules permitting, foreign ministers from Britain, France, Germany, Russia and China will join their U.S. and Iranian counterparts, along with EU foreign policy chief Catherine Ashton, Harf said.
(Reporting by Louis Charbonneau; Editing by Peter Cooney)