The foreign ministers of six world powers are to join ongoing negotiations in Austria on Iran's nuclear program. The talks seek to reach a comprehensive agreement by July 20th, the self-imposed deadline.
A spokesperson for European Union foreign policy chief Catherine Ashton said the ministers of the six countries have been invited to monitor the progress in the talks.
The negotiations, which began on July 2nd in Vienna, have been largely conducted by Ashton and Iranian Foreign Minister Mohammad Javad Zarif.
US State Department deputy spokesperson Marie Harf said on her Twitter account on Thursday that Secretary of State John Kerry will travel to Vienna this weekend.
French government sources told NHK that Foreign Minister Laurent Fabius will arrive in Vienna on Sunday to join the talks.
Negotiators remain sharply at odds over the scale of Iran's uranium enrichment program, including the number of centrifuges it can use.
They are also divided over how to lift economic sanctions imposed by Western nations.
Jul. 11, 2014 - Updated 00:50 UTC