Rouhani says solutions reached on 'key parameters' in nuclear talks.

Iran's President Hassan Rouhani said Thursday that solutions on "key parameters" of a nuclear deal with six world powers had been reached and drafting of an agreement would begin immediately.

The text of a binding agreement "is to finish by June 30th" Rouhani added in a tweet sent minutes before a joint statement between Iran and the P5+1 group of leading nations was to be made in Lausanne, Switzerland.